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2Q TWENTY24 INVESTOR PRESENTATION ORIGIN BANCORP, INC.

2 FORWARD-LOOKING STATEMENTS AND NON-GAAP MEASURES This presentation contains certain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements include information regarding Origin Bancorp, Inc.'s ("Origin" or the "Company") future financial performance, business and growth strategies, projected plans and objectives, and any expected purchases of its outstanding common stock, and related transactions and other projections based on macroeconomic and industry trends, including changes to interest rates by the Federal Reserve and the resulting impact on Origin's results of operations, estimated forbearance amounts and expectations regarding the Company's liquidity, including in connection with advances obtained from the FHLB, which are all subject to change and may be inherently unreliable due to the multiple factors that impact broader economic and industry trends, and any such changes may be material. Such forward-looking statements are based on various facts and derived utilizing important assumptions and current expectations, estimates and projections about Origin and its subsidiaries, any of which may change over time and some of which may be beyond Origin's control. Statements or statistics preceded by, followed by or that otherwise include the words "assumes," "anticipates," "believes," "estimates," "expects," “foresees,” "intends," "plans," "projects," and similar expressions or future or conditional verbs such as "could," "may," “might,” "should," "will," and "would" and variations of such terms are generally forward-looking in nature and not historical facts, although not all forward-looking statements include the foregoing words. Further, certain factors that could affect the Company's future results and cause actual results to differ materially from those expressed in the forward-looking statements include, but are not limited to: potential impacts of adverse developments in the banking industry highlighted by high-profile bank failures, including impacts on customer confidence, deposit outflows, liquidity and the regulatory response thereto; the impact of current and future economic conditions generally and in the financial services industry, nationally and within Origin’s primary market areas, including the effects of declines in the real estate market, high unemployment rates, inflationary pressures, elevated interest rates and slowdowns in economic growth, as well as the financial stress on borrowers and changes to customer and client behavior as a result of the foregoing; potential reductions in benchmark interest rates and the resulting impacts on net interest income; deterioration of Origin's asset quality; factors that can impact the performance of Origin's loan portfolio, including real estate values and liquidity in Origin's primary market areas; the financial health of Origin's commercial borrowers and the success of construction projects that Origin finances; changes in the value of collateral securing Origin's loans; developments in our mortgage banking business, including loan modifications, general demand, and the effects of judicial or regulatory requirements or guidance; Origin's ability to anticipate interest rate changes and manage interest rate risk (including the impact of higher interest rates on macroeconomic conditions, competition, and the cost of doing business and the impact of prolonged elevated interest rates on our financial projections, models and guidance); the effectiveness of Origin's risk management framework and quantitative models; Origin's inability to receive dividends from Origin Bank and to service debt, pay dividends to Origin's common stockholders, repurchase Origin's shares of common stock and satisfy obligations as they become due; the impact of labor pressures; changes in Origin's operation or expansion strategy or Origin's ability to prudently manage its growth and execute its strategy; changes in management personnel; Origin's ability to maintain important customer relationships, reputation or otherwise avoid liquidity risks; increasing costs as Origin grows deposits; operational risks associated with Origin's business; significant turbulence or a disruption in the capital or financial markets and the effect of a fall in stock market prices on our investment securities; increased competition in the financial services industry, particularly from regional and national institutions, as well as from fintech companies, difficult market conditions and unfavorable economic trends in the United States generally, and particularly in the market areas in which Origin operates and in which its loans are concentrated; Origin's level of nonperforming assets and the costs associated with resolving any problem loans including litigation and other costs; the credit risk associated with the substantial amount of commercial real estate, construction and land development, and commercial loans in Origin's loan portfolio; changes in laws, rules, regulations, interpretations or policies relating to financial institutions, and potential expenses associated with complying with such regulations; periodic changes to the extensive body of accounting rules and best practices; further government intervention in the U.S. financial system; a deterioration of the credit rating for U.S. long-term sovereign debt or actions that the U.S. government may take to avoid exceeding the debt ceiling; a potential U.S. federal government shutdown and the resulting impacts; compliance with governmental and regulatory requirements, including the Dodd-Frank Wall Street Reform and Consumer Protection Act and others relating to banking, consumer protection, securities, and tax matters; Origin's ability to comply with applicable capital and liquidity requirements, including its ability to generate liquidity internally or raise capital on favorable terms, including continued access to the debt and equity capital markets; changes in the utility of Origin's non-GAAP liquidity measurements and its underlying assumptions or estimates; possible changes in trade, monetary, and fiscal policies, laws, and regulations and other activities of governments, agencies and similar organizations; natural disasters and adverse weather events, acts of terrorism, an outbreak of hostilities (including the impacts related to or resulting from Russia's military action in Ukraine, or the conflict in Israel and surrounding areas, including the imposition of additional sanctions and export controls, as well as the broader impacts to financial markets and the global macroeconomic and geopolitical environments), regional or national protests and civil unrest (including any resulting branch closures or property damage), widespread illness or public health outbreaks or other international or domestic calamities, and other matters beyond Origin's control; the impact of generative artificial intelligence; fraud or misconduct by internal or external actors (including Origin employees) which Origin may not be able to prevent, detect or mitigate, system failures, cybersecurity threats or security breaches and the cost of defending against them; Origin’s ability to maintain adequate internal controls over financial and non- financial reporting; and potential claims, damages, penalties, fines, costs and reputational damage resulting from pending or future litigation, regulatory proceedings and enforcement actions. For a discussion of these and other risks that may cause actual results to differ from expectations, please refer to the sections titled "Cautionary Note Regarding Forward-Looking Statements" and "Risk Factors" in Origin's most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission ("SEC") and any updates to those sections set forth in Origin's subsequent Quarterly Reports on Form 10-Q and Current Reports on Form 8-K. If one or more events related to these or other risks or uncertainties materialize, or if Origin's underlying assumptions prove to be incorrect, actual results may differ materially from what Origin anticipates. Accordingly, you should not place undue reliance on any forward-looking statements. Any forward-looking statement speaks only as of the date on which it is made, and Origin does not undertake any obligation to publicly update or review any forward-looking statement, whether as a result of new information, future developments, or otherwise. New risks and uncertainties arise from time to time, and it is not possible for Origin to predict those events or how they may affect Origin. In addition, Origin cannot assess the impact of each factor on Origin's business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements. All forward-looking statements, expressed or implied, included in this communication are expressly qualified in their entirety by this cautionary statement. This cautionary statement should also be considered in connection with any subsequent written or oral forward-looking statements that Origin or persons acting on Origin's behalf may issue. Annualized, pro forma, adjusted projected and estimated numbers are used for illustrative purposes only, are not forecasts, and may not reflect actual results. Certain prior period amounts have been reclassified to conform to the current year financial statement presentations. These reclassifications did not impact previously reported net income or comprehensive income. Origin reports its results in accordance with generally accepted accounting principles in the United States ("GAAP"). However, management believes that certain supplemental non-GAAP financial measures may provide meaningful information to investors that is useful in understanding Origin's results of operations and underlying trends in its business. However, non-GAAP financial measures are supplemental and should be viewed in addition to, and not as an alternative for, Origin's reported results prepared in accordance with GAAP. The following are the non-GAAP measures used in this presentation: PTPP earnings, adjusted NIM-FTE, PTPP ROAA, tangible book value per common share, adjusted tangible book value per common share, tangible common equity, adjusted tangible common equity, tangible common equity to tangible assets, return on average tangible common equity and core efficiency ratio. Please see “Reconciliation of Non-GAAP Financial Measures” at the end of this presentation for reconciliations of non-GAAP measures to the most directly comparable financial measures calculated in accordance with GAAP. ORIGIN BANCORP, INC. _______

ORIGIN BANCORP, INC. _______ LOUISIANA Entry: 1912 Loans: $1,439 Deposits: $2,805 DOLLARS IN MILLIONS, UNAUDITED (1) (2) 3 DEPOSITS & LOANS BY STATE Note: All financial information is as of June 30, 2024. Map location counts include full service branches only. Please see slide 29 for all footnote references included above. MISSISSIPPI Entry: 2010 Loans: $592 Deposits: $581 7% 8% 33% 19% 60% 73% Loans (2)Deposits (1) ICS ICS TEXAS Dallas/Fort Worth Houston East Texas Entry: 2008 Entry: 2013 Entry: 2022 Loans: $3,004 Loans: $1,980 Loans: $432 Deposits: $2,828 Deposits: $1,303 Deposits: $898 Total Texas Loans: $5,416 Total Texas Deposits: $5,029 SOUTHEAST Entry: 2024(3) 16 10 9 18 6 ** *Locations in Mobile, Alabama and Fort Walton Beach, Florida coming soon

Net Domestic Migration from April 1, 2020 to July 1, 2023 l Source: US Census Bureau STRONG NET MIGRATION INTO OUR MARKETS WEST -774,966 MIDWEST -480,336 NORTHEAST -1,181,700 SOUTH +2,437,002 4 TEXAS SOUTH ALABAMA & FLORIDA PANHANDLE l Baldwin County - 7th fastest growing metro in the country l High-tech employment population l 7 of top 10 US defense contractors have a presence in the region l Mobile, AL - 12th largest US port by volume l Mobile Harbor project will make it the deepest harbor in the Gulf of Mexico in 2025 l 8th largest economy in the world l #1 in jobs created in 2023 with 369,600 jobs added l Home to 55 fortune 500 company headquarters l Texas boasts the 2nd largest civilian workforce in the US with over 15 million workers l Texas is the leading destination for corporate relocation & expansion projects l Texas is home to 3.2 million small businesses and hundreds of publicly traded firms l Texas led the nation in high tech exports for the 11th year in a row in 2023 ORIGIN STRATEGICALLY INVESTS I N T E X A S & S O U T H E A S T THE MOST DYNAMIC GROWTH MARKETS IN THE COUNTRY

5 ORIGIN BANCORP, INC. _______

ORIGIN BANCORP, INC. _______ • Total LHFI were $7.96 billion at June 30, 2024, reflecting an increase of $59.1 million, or 0.7%, compared to March 31, 2024. LHFI, excluding MW LOC, were $7.45 billion at June 30, 2024, reflecting a decrease of $46.4 million, or 0.6%, compared to March 31, 2024. • Total deposits were $8.51 billion reflecting an increase of $5.4 million, or 0.1%, compared to March 31, 2024. • Noninterest income was $22.5 million for the quarter ended June 30, 2024, reflecting an increase of $5.2 million, or 30.2%, compared to the linked quarter, and was at the highest level in our history since we became a publicly traded Company in 2018. • Our book value per common share was $35.23 at June 30, 2024, reflecting an increase of $0.44, or 1.3%, compared to March 31, 2024. Tangible book value per common share was $29.77 at June 30, 2024, reflecting an increase of $0.53, or 1.8%, compared to March 31, 2024. • June 30, 2024, Company level common equity Tier 1 capital to risk-weighted assets was 12.15%, Tier 1 leverage ratio was 10.70%, and the total capital ratio was 15.16%. Key Performance Metrics 2Q24 1Q24 B al an ce S he et Total Loans Held for Investment ("LHFI") $ 7,959,171 $ 7,900,027 Total Assets 9,947,182 9,892,379 Total Deposits 8,510,842 8,505,464 In co m e St at em en t Net Income $ 20,989 $ 22,632 Pre-Tax, Pre-Provision ("PTPP") Earnings(4) 31,967 31,871 Adjusted Net Income(3) Diluted EPS 0.67 0.73 Se le ct ed R at io s NIM - FTE 3.17 % 3.19 % Return on Average Assets (annualized) ("ROAA") 0.84 0.92 PTPP ROAA (annualized)(4) 1.28 1.30 Return on Average Stockholders’ Equity (annualized) ("ROAE") 7.79 8.57 Book Value per Common Share $ 35.23 $ 34.79 Tangible Book Value per Common Share(4) 29.77 29.24 Adjusted Tangible Book Value per Common Share(4) 33.86 33.27 Tangible Common Equity to Tangible Assets(4) 9.47 % 9.33 % Return on Average Tangible Common Equity (annualized) ("ROATCE")(4) 9.25 10.24 Efficiency Ratio 66.82 64.81 Core Efficiency Ratio(4) 65.55 65.24 ALCL to Total LHFI 1.27 1.25 DOLLARS IN THOUSANDS, EXCEPT PER SHARE AMOUNTS UNAUDITED 6 PERFORMANCE HIGHLIGHTS AT-A-GLANCE - SECOND QUARTER 2024 2Q24 Key Highlights Please see slide 29 for all footnote references included above.

ORIGIN BANCORP, INC. _______ TRENDING KEY MEASURES UNAUDITED Diluted EPS ($)Net Income ($) Total LHFI, Adjusted(5) ($) Total Deposits ($) 3Q 20 4Q 20 1Q 21 2Q 21 3Q 21 4Q 21 1Q 22 2Q 22 3Q 22 4Q 22 1Q 23 2Q 23 3Q 23 4Q 23 1Q 24 2Q 24 3Q 20 4Q 20 1Q 21 2Q 21 3Q 21 4Q 21 1Q 22 2Q 22 3Q 22 4Q 22 1Q 23 2Q 23 3Q 23 4Q 23 1Q 24 2Q 24 8,511 3Q 20 4Q 20 1Q 21 2Q 21 3Q 21 4Q 21 1Q 22 2Q 22 3Q 22 4Q 22 1Q 23 2Q 23 3Q 23 4Q 23 1Q 24 2Q 24 4,043 7,453 3Q 20 4Q 20 1Q 21 2Q 21 3Q 21 4Q 21 1Q 22 2Q 22 3Q 22 4Q 22 1Q 23 2Q 23 3Q 23 4Q 23 1Q 24 2Q 24 DOLLARS IN THOUSANDS 7 Total LHFI ($) DOLLARS IN MILLIONS 5,613 7,959 3Q 20 4Q 20 1Q 21 2Q 21 3Q 21 4Q 21 1Q 22 2Q 22 3Q 22 4Q 22 1Q 23 2Q 23 3Q 23 4Q 23 1Q 24 2Q 24 DOLLARS IN MILLIONS DOLLARS IN MILLIONS Please see slide 29 for all footnote references included above. CAGR 9.8% CAGR 17.7% CAGR 10.1% 5,936 13,095 20,989 Core Efficiency Ratio(4) (%) (Non-GAAP) 56.55 65.55 3Q 20 4Q 20 1Q 21 2Q 21 3Q 21 4Q 21 1Q 22 2Q 22 3Q 22 4Q 22 1Q 23 2Q 23 3Q 23 4Q 23 1Q 24 2Q 24 25.39 29.77 3Q 20 4Q 20 1Q 21 2Q 21 3Q 21 4Q 21 1Q 22 2Q 22 3Q 22 4Q 22 1Q 23 2Q 23 3Q 23 4Q 23 1Q 24 2Q 24 Tangible Book Value per Common Share(4) ($) (Non-GAAP) 24.46 33.86 3Q 20 4Q 20 1Q 21 2Q 21 3Q 21 4Q 21 1Q 22 2Q 22 3Q 22 4Q 22 1Q 23 2Q 23 3Q 23 4Q 23 1Q 24 2Q 24 Adj Tangible Book Value per Common Share(4) ($) (Non-GAAP) CAGR 4.3% CAGR 9.1% 0.56 0.67

ORIGIN BANCORP, INC. _______ ASSET AND STOCKHOLDERS' EQUITY GROWTH 1997 - 2Q24 DOLLARS IN MILLIONS Total Assets ($) 148 9,947 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 20 11 20 12 20 13 20 14 20 15 20 16 20 17 20 18 20 19 20 20 20 21 20 22 20 23 2Q 24 Total Stockholders' Equity ($) 11 1,096 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 20 11 20 12 20 13 20 14 20 15 20 16 20 17 20 18 20 19 20 20 20 21 20 22 20 23 2Q 24 CAGR 17.2% CAGR 18.8% 8 Origin Bancorp, Inc. Cumulative Return ($) KBW Nasdaq Bank Total Return Index ($) 12 /3 1/ 96 12 /3 1/ 97 12 /3 1/ 98 12 /3 1/ 99 12 /3 1/ 00 12 /3 1/ 01 12 /3 1/ 02 12 /3 1/ 03 12 /3 1/ 04 12 /3 1/ 05 12 /3 1/ 06 12 /3 1/ 07 12 /3 1/ 08 12 /3 1/ 09 12 /3 1/ 10 12 /3 1/ 11 12 /3 1/ 12 12 /3 1/ 13 12 /3 1/ 14 12 /3 1/ 15 12 /3 1/ 16 12 /3 1/ 17 12 /3 1/ 18 12 /3 1/ 19 12 /3 1/ 20 12 /3 1/ 21 12 /3 1/ 22 12 /3 1/ 23 0 500 1,000 1,500 2,000 2,500 Total Shareholder Return(6) ($) IPO Please see slide 29 for all footnote references included above. DOLLARS IN MILLIONS UNAUDITED

ORIGIN BANCORP, INC. _______ 9 2,247 2,620 4,747 5,276 5,416 1,343 1,545 2,747 2,993 3,004 904 1,075 1,631 1,837 1,980 369 446 432 DFW Houston East Texas 2020 2021 2022 2023 2Q24 Deposit Trends by Texas Market(1) ($) Loan Trends by Texas Market(2) ($) TEXAS GROWTH STORY Texas Franchise Highlights DOLLARS IN MILLIONS • 35 locations throughout 10 counties including the 4th and 5th largest MSAs in the United States.(7) • Texas franchise represents 73% of LHFI(2) and 60% of deposits(1) at June 30, 2024. 2,574 3,132 4,261 4,108 5,029 1,581 1,925 2,196 1,994 2,828 993 1,207 1,173 1,205 1,303 892 909 898 DFW Houston East Texas 2020 2021 2022 2023 2Q24 CAGR 28.6% CAGR 21.1% Please see slide 29 for all footnote references included above. DOLLARS IN MILLIONS UNAUDITED

ORIGIN BANCORP, INC. _______ 10 LOAN GROWTH 4,094 4,498 6,805 7,331 7,453 4,094 4,498 5,593 7,331 7,453 1,212 Origin BTH 2020 2021 2022 2023 2Q24 0 2,000 4,000 6,000 8,000 LHFI Key Data DOLLARS IN MILLIONS IDT • Total LHFI, excluding MW LOC, were $7.45 billion at June 30, 2024, reflecting a decrease of $46.4 million, or 0.6%, compared to March 31, 2024. • Total MW LOC were $506.5 million, or 6.4%, of total LHFI at June 30, 2024. LHFI Growth excluding MW LOC(8) ($) 1,732 1,872 2,894 3,013 3,031 1,732 1,872 2,267 3,013 3,031 627 Origin BTH 2020 2021 2022 2023 2Q24 0 1,000 2,000 3,000 4,000 C&I and Owner Occupied CRE Growth(8) ($) Please see slide 29 for all footnote references included above. DOLLARS IN MILLIONS UNAUDITED

ORIGIN BANCORP, INC. _______ Commercial & Industrial ("C&I") 27% Owner Occupied Commercial Real Estate ("CRE")Non-Owner Occupied CRE C&D: 13% Multi- Family Real Estate Residential Real Estate - Single Family & Consumer Real Estate & Construction: 9% Retail Shopping: 6% Office Building: 5% Multi-Family Real Estate: 5% Multi-Family under Construction: 3% Healthcare: 2% Hotel: 1% Consumer: 1% Restaurant: 1% Professional Svcs.: 1% Finance & Insurance: 1% Misc.: 2% Finance & Insurance: 7% Real Estate & Construction: 7% MW LOC: 6% Energy: 4% Transportation Svcs: 2% Retail Shopping: 2% Healthcare: 2% Retail Dealers: 2% Restaurants: 1% Professional Svcs: 1% Entertainment: 1% Consumer Svcs: 1% Commercial Svcs: 1% Wholesale Distribution: 1% Banks: 1% Misc: 6% 11 WELL DIVERSIFIED LOAN PORTFOLIO (Dollars in thousands) 2Q24 1Q24 4Q23 3Q23 2Q23 C&I $ 2,070,947 $ 2,154,151 $ 2,059,460 $ 2,058,073 $ 1,977,028 Owner Occupied CRE 959,850 948,624 953,822 932,109 915,861 MW LOC 506,505 400,995 329,966 286,293 537,627 Total Commercial 3,537,302 3,503,770 3,343,248 3,276,475 3,430,516 Non-Owner Occupied CRE 1,563,152 1,472,164 1,488,912 1,503,782 1,512,303 C&D 1,017,389 1,168,597 1,070,225 1,076,756 1,022,239 Multi-Family Real Estate 398,202 359,765 361,239 349,787 348,703 Residential Real Estate- Single Family 1,421,027 1,373,532 1,373,696 1,338,382 1,284,955 Consumer Loans 22,099 22,199 23,624 22,881 23,973 Total Loans $ 7,959,171 $ 7,900,027 $ 7,660,944 $ 7,568,063 $ 7,622,689 Loan Portfolio Details Non-Owner Occupied CRE, C&D and Multi-Family: $2,979 million C&I, Owner Occupied CRE and MW LOC: $3,537 million C&I, Owner Occupied CRE, MW LOC: 45% Non-Owner Occupied CRE, C&D, Multi-Family: 37% Loan Composition at June 30, 2024: $7,959 million Please see slide 29 for all footnote references included above. UNAUDITED (9) MW LOC 5% 18% 12% 6%19%

ORIGIN BANCORP, INC. _______ 1.11 0.85 1.05 1.07 1.49 0.10 0.14 0.10 0.13 0.15 Classified LHFI / Total LHFI (%) Net Charge-Offs / Average LHFI (annualized) 2Q23 3Q23 4Q23 1Q24 2Q24 0.44 0.42 0.39 0.51 0.95 0.26 0.27 0.34 0.42 0.83 Nonperforming LHFI / LHFI (%) Past due LHFI / LHFI (%) 2Q23 3Q23 4Q23 1Q24 2Q24 12 CREDIT QUALITY Asset Quality Trends (%) Allowance for Loan Credit Losses ("ALCL") 94,353 95,177 96,868 98,375 100,865 1.24 1.26 1.26 1.25 1.27 1.32 1.30 1.31 1.30 1.34 ALCL as a percentage of LHFI, adjusted (%) ALCL as a percentage of LHFI (%) ALCL ($) 2Q23 3Q23 4Q23 1Q24 2Q24 • Recently, we identified certain questioned activity involving a single banker in our East Texas market. The activity involved the former banker facilitating advances in and among certain customer loans and accounts that, in one or more instances, may not have been appropriately documented. This activity negatively impacted our provision expense during the quarter. • Provision for loan credit loss expense for 2Q24 was $5.4 million, compared to $4.1 million in 1Q24, and $4.3 million in 2Q23. The $1.3 million net increase in the provision for loan credit losses was driven primarily by a total $7.3 million increase associated with the first bulleted item above, representing a $4.1 million provision on impacted relationships and a $3.2 million provision related to the questioned banker activity. • ALCL to nonperforming LHFI is 133.05% at 2Q24, 243.27% at 1Q24, and 280.74% at 2Q23. DOLLARS IN THOUSANDS (10) Please see slide 29 for all footnote references included above. UNAUDITED

ORIGIN BANCORP, INC. _______ Texas: 75% Louisiana: 6% Mississippi: 13% Out of Market: 6% 13 Medical: 25% Financial: 15% Law Firms: 11%Energy: 10% Other: 24% National Credit Tenant: 15% CRE OFFICE - STRENGTH AND DIVERSIFICATION Tenant Classification $373.8M $373.8M Geographic Diversification DOLLARS IN THOUSANDS June 30, 2024 Avg. Loan Size $ 2,336 Weighted Avg. LTV 59.19 % Past Due Loans / Loans — Classified Loans / Loans — NPL / Loans — NCOs / Avg. Loans (annualized) — ALCL / Loans 0.77 Key Portfolio Metrics DOLLARS IN MILLIONS DOLLARS IN MILLIONS NON-OWNER OCCUPIED (“NOO”), UNAUDITED Sensitivity Analysis(11) (%) 1.34 1.10 54.70 80.44 Current DSC Stressed DSC Current LTV Stressed LTV NOO CRE Office (12) Please see slide 29 for all footnote references included above. (13)

ORIGIN BANCORP, INC. _______ 14 SELECTED SECTORS - KEY PORTFOLIO METRICS June 30, 2024 Multi-Family Real Estate + Under Construction Hotel Retail Shopping Outstanding Loan Balance $ 655,151 $ 107,933 $ 647,346 % of LHFI 8.23 % 1.36 % 8.13 % Avg. Loan Size $ 3,165 $ 4,906 $ 1,575 Weighted Avg. LTV 57.06 % 59.15 % 64.54 % Past Due Loans / Loans — — 0.20 Classified Loans / Loans 0.42 1.86 0.28 NPL / Loans 0.01 — — NCOs / Avg. Loans (annualized) — — (0.01) ALCL / Loans 0.90 1.05 0.69 DOLLARS IN THOUSANDS, UNAUDITED

ORIGIN BANCORP, INC. _______ Treasury/Agency: 4% MBS: 48% CMO: 14% Municipal: 24% Corporate/ABS: 10% 1,592 1,527 1,291 1,244 1,190 2.42 2.46 2.50 2.51 2.54 Total Securities ($) Yield (%) 2Q23 3Q23 4Q23 1Q24 2Q24 Investment Securities Average Balance and Yield INVESTMENT SECURITIES DOLLARS IN MILLIONS • Total securities portfolio weighted average effective duration was 4.28 years as of June 30, 2024, compared to 4.34 years as of March 31, 2024. • Expected principal cash flows from investments with no rate changes: • 2024: $73.8 million • 2025: $107.6 million • 2026: $129.5 million 15 (152.9) (172.7) (121.0) (124.9) (127.2) 2Q23 3Q23 4Q23 1Q24 2Q24 Accumulated Other Comprehensive Loss(14) ($) Investment Securities - AFS Please see slide 29 for all footnote references included above. $1.16B DOLLARS IN MILLIONS UNAUDITED

ORIGIN BANCORP, INC. _______ Total Loans (Dollars in thousands) Repricing or Maturity Term Rate Structure 1 Year or less > 1 to 3 Years > 3 to 5 Years > 5 to 10 Years > 10 Years Total Floating Rate Variable Rate Fixed Rate Commercial and industrial $ 1,619,947 $ 222,924 $ 195,639 $ 32,107 $ 330 $ 2,070,947 $ 1,625,026 $ 1,440 $ 444,481 Owner Occupied CRE 244,899 223,780 316,972 173,352 847 959,850 233,492 5,242 721,116 MW LOC 506,505 — — — — 506,505 506,505 — — Total Commercial $ 2,371,351 $ 446,704 $ 512,611 $ 205,459 $ 1,177 $ 3,537,302 $ 2,365,023 $ 6,682 $ 1,165,597 Non-Owner Occupied CRE 602,581 456,524 376,196 127,851 — 1,563,152 523,176 2,824 1,037,152 C&D 669,125 193,185 114,231 23,449 17,399 1,017,389 620,987 37,372 359,030 Multi-Family Real Estate 149,803 168,450 53,626 20,273 6,050 398,202 116,616 — 281,586 Residential Real Estate - Single Family 258,132 208,224 470,801 282,866 201,004 1,421,027 211,399 742,696 466,932 Consumer 10,577 7,100 3,928 454 40 22,099 5,473 121 16,505 Total $ 4,061,569 $ 1,480,187 $ 1,531,393 $ 660,352 $ 225,670 $ 7,959,171 $ 3,842,674 $ 789,695 $ 3,326,802 % of total 51 % 19 % 19 % 8 % 3 % 100 % 48 % 10 % 42 % Weighted Average Coupon Rate 7.75 % 4.67 % 5.76 % 4.34 % 4.94 % 6.43 % 7.90 % 4.67 % 5.16 % AFS & HTM Securities (Dollars in thousands) Maturity & Projected Principal Cashflow Total1 Year or less > 1 to 3 Years > 3 to 5 Years > 5 to 10 Years > 10 Years Projected cash flow $ 127,156 $ 260,299 $ 258,561 $ 464,491 $ 201,134 $ 1,311,641 % of Total 10 % 20 % 20 % 35 % 15 % 100 % LOANS & SECURITIES- REPRICING OR MATURITY 16 Please see slide 29 for all footnote references included above. UNAUDITED

ORIGIN BANCORP, INC. _______ Commercial: 52% Consumer: 31% Public: 10% Brokered: 7% Finance & Insurance: 7% Real Estate Rental & Leasing: 6% Construction: 6% Professional, Scientific, & Technical Svcs: 5% Other Business Deposits 2% or less: 4% Mgmt of Companies & Enterprises: 3% Affiliate: 3% Manufacturing: 2% Healthcare & Social Assistance: 2% Other Svcs (except Public Admin.): 2% Mining: 2% Wholesale Trade: 1% Retail Trade: 1% Misc: 8% 17 DEPOSIT DETAIL (Dollars in thousands) 2Q24 1Q24 4Q23 3Q23 2Q23 QoQ % Δ Total Deposits $ 8,510,842 $ 8,505,464 $ 8,251,125 $ 8,374,488 $ 8,490,043 0.1 % FDIC Insured (3,442,636) (3,447,538) (3,425,268) (3,434,530) (3,402,826) (0.1) FDIC Insured Reciprocal (799,221) (801,145) (801,699) (781,054) (770,823) (0.2) FDIC Insured Brokered Deposits (636,814) (597,110) (444,989) (669,202) (677,909) 6.6 Total Estimated FDIC Uninsured Deposits 3,632,171 3,659,671 3,579,169 3,489,702 3,638,485 (0.8) Collateralized Public Funds (771,419) (836,150) (849,603) (739,329) (799,351) (7.7) Uninsured/ Uncollateralized Deposits ($) $ 2,860,752 $ 2,823,521 $ 2,729,566 $ 2,750,373 $ 2,839,134 1.3 Uninsured/ Uncollateralized Deposits (%) 33.6 % 33.2 % 33.1 % 32.8 % 33.4 % Deposit Detail Geographic Concentration(1) Commercial Deposit Composition: $4,405 millionDeposit Composition at June 30, 2024(15): $8,511 million Commercial Public Funds 37% 20%7% 31% 5% Consumer MississippiLouisiana Texas- DFW TX- East TexasTexas- Houston 17% 17% 18% 38% 10% 14% 4% 13% 52% 17% Please see slide 29 for all footnote references included above. UNAUDITED

ORIGIN BANCORP, INC. _______ 18 8,260 8,443 8,361 8,439 8,559 4,741 4,728 4,785 5,009 5,130 2,140 2,088 1,973 1,866 1,894 1,379 1,627 1,603 1,564 1,535 Interest-bearing Demand Noninterest-bearing Time Deposits 2Q23 3Q23 4Q23 1Q24 2Q24 Average Deposits ($) DEPOSIT TRENDS Deposit Cost Trends (QTD Annualized) (%) IDT Total Deposit Beta (%) DOLLARS IN MILLIONS UNAUDITED 0.00 0.51 0.19 1.22 (0.02) 0.02 0.22 0.61 0.73 0.51 0.35 0.23 0.15 0.09 Change in Cost of Total Deposits 1Q22 2Q22 3Q22 4Q22 1Q23 2Q23 3Q23 4Q23 1Q24 2Q24 Change in Cost of Total Deposits (%) 0.170.29 -50.00 10.48 23.25 35.21 42.16 46.72 50.48 53.33 55.05 0.12 0.77 2.18 3.65 4.51 4.99 5.26 5.33 5.33 5.33 Cumulative Deposit Beta Average Quarterly Fed Funds Rate 1Q22 2Q22 3Q22 4Q22 1Q23 2Q23 3Q23 4Q23 1Q24 2Q24 0.54 0.49 2.58 3.56 4.04 4.24 4.35 4.46 0.26 0.64 1.54 2.49 3.05 3.47 3.71 3.85 3.95 0.41 1.02 1.75 2.26 2.61 2.84 2.99 3.08 Time Deposits Cost of Interest-bearing Deposits Cost of Total Deposits 1Q22 2Q22 3Q22 4Q22 1Q23 2Q23 3Q23 4Q23 1Q24 2Q24

ORIGIN BANCORP, INC. _______ 19 YIELDS AND COSTS Yield on LHFI (%) Cost of Funds (%) • At 2Q24, LHFI with fixed rates = 42% and LHFI with floating/variable rates = 58%. • At 2Q24, Prime-based = $2.05 billion, SOFR-based = $2.25 billion and other index-based loans = $332.4 million. UNAUDITED 6.18 6.35 6.46 6.58 6.58 6.16 6.35 6.47 6.58 6.58 8.16 8.43 8.50 8.50 8.50 4.92 5.20 5.33 5.33 5.33 Yield on LHFI Yield on LHFI excl. PAA Avg. Prime Rate 30 Day Avg. SOFR 2Q23 3Q23 4Q23 1Q24 2Q24 (16) Please see slide 29 for all footnote references included above. 2.52 2.74 2.89 3.04 3.123.05 3.47 3.71 3.85 3.95 2.26 2.61 2.84 2.99 3.08 Cost of Total Deposits & Borrowings Cost of Interest Bearing Deposits Cost of Total Deposits 2Q23 3Q23 4Q23 1Q24 2Q24

ORIGIN BANCORP, INC. _______ 75,291 74,130 72,989 73,323 73,890 68,346 67,292 67,775 67,540 65,781 6,415 6,838 5,214 5,783 8,109 3.16 3.14 3.19 3.19 3.17 3.14 3.14 3.19 3.19 3.17 Net Interest Income excl. MW LOC, adjusted MW LOC Interest Income Net Purchase Accounting Accretion NIM (FTE) Adjusted NIM (FTE) 2Q23 3Q23 4Q23 1Q24 2Q24 20 DOLLARS IN THOUSANDS, UNAUDITED NET INTEREST INCOME AND NIM TRENDS 3.19 0.06 0.04 0.02 0.01 0.01 (0.05) (0.11) 1Q 24 MW LO C Rea l E sta te Lo an s Equ ity S ec . H eld in ot hr. In st. To tal S ec ur itie s IB B al. D FB Int R ev er sa l Q ue sti on ed A ct. Sav ing s a nd IB Tr an sc . A cc ts 2Q 24 2.00 3.00 (17) (18) Please see slide 29 for all footnote references included above. 24.64 29.52 21.01 8.58 2.04 2.480.12 0.77 2.18 3.65 4.99 5.26 5.33 5.33 Cumulative NIM-FTE Beta Average Quarterly Fed Funds Rate 1Q22 2Q22 3Q22 4Q22 2Q23 3Q23 4Q23 1Q24 2Q24 NIM Beta - 2Q24 (%) 1.54 2.48 4.51 NIM-FTE Changes - 2Q24 (%) NIM-FTE Changes - 2Q24 (%) 73,32372,989 1,362 1,537 568 432 (298) (3,267) 4Q 23 RE Lo an s C&I MW LO C Othe r FH LB & O the r Bor ro wing s Sav ing s & IB Tr an sa c. Acc ts. 1Q 24 40,000 60,000 80,000 • In June 2024, the Federal Reserve left the current fed funds rate steady at a 23-year high of 5.25% to 5.50%. • As mentioned on slide 12, recently, we identified certain questioned activity involving a single banker in our East Texas market. Several of the relationships impacted by this activity were placed on non- accrual, resulting in a reversal of $1.2 million of accrued interest which negatively impacted the fully tax equivalent NIM-FTE by five basis points. • As we navigate through stabilizing rate conditions, our strategic focus continues to align with offering attractive returns to our depositors while closely monitoring economic indicators and federal funds rate projections for informed decision-making. Net Interest Income & NIM ($) 3.17 530

ORIGIN BANCORP, INC. _______ 14,299 13,962 13,503 16,648 15,809 6,185 6,443 5,446 7,725 6,665 4,722 4,621 4,889 4,688 4,862 1,990 2,006 2,118 2,247 2,404 1,402 892 1,050 1,988 1,878 Insurance Commission & Fee Income Service Charges & Fees Other Fee Income Mortgage Banking Revenue 2Q23 3Q23 4Q23 1Q24 2Q24 21 90,927 92,249 81,185 90,578 96,355 Net Interest Income Noninterest Income 2Q23 3Q23 4Q23 1Q24 2Q24 Major Components of Noninterest Income(19) ($) Net Interest Income + Noninterest Income ($) NET REVENUE DISTRIBUTION Components of Other Noninterest Income ($) 2Q24 1Q24 4Q23 3Q23 2Q23 Swap Fee Income 44 57 196 366 331 Gain on Subordinated Debentures 81 — — — 471 (Loss) Gain on Sale of Securities — (403) (4,606) (7,173) — Positive Valuation Adj. on Non-Marketable Equity Securities 5,188 — — 10,096 — MSR Gain (Impairment) — 410 (1,769) — — Gain on Bank Property Sale 800 — — — — Other 543 543 872 868 535 Total $ 6,656 $ 607 $ (5,307) $ 4,157 $ 1,337 82.8% 76.7% Please see slide 29 for all footnote references included above. DOLLARS IN THOUSANDS, UNAUDITED 81.0%89.9%80.4%

ORIGIN BANCORP, INC. _______ 22 Efficiency Ratios (%) NONINTEREST EXPENSE ANALYSIS DOLLARS IN THOUSANDS Noninterest Expense Composition ($) Consolidated Efficiency Ratio Core Efficiency Ratio 2Q23 3Q23 4Q23 1Q24 2Q24 Operating Leverage (%) E FF IC IE N C Y R AT IO (% ) N IE / AV E R A G E A S S E TS (% ) 2.32 2.32 2.48 2.39 2.59 64.76 63.59 75.02 64.81 66.82 2Q23 3Q23 4Q23 1Q24 2Q24 40 60 80 100 1.5 2.0 2.5 3.0 64 .7 6 60 .8 2 60 .4 9 63 .5 9 Please see slide 29 for all footnote references included above. 70 .5 5 66 .8 2 (4) UNAUDITED 65 .5 5 75 .0 2 64 .8 1 65 .2 458,887 58,663 60,906 58,707 64,388 34,533 34,624 35,931 35,818 38,109 6,578 6,790 6,912 6,645 7,009 2,837 2,775 3,062 3,145 3,468 2,552 2,264 2,259 2,137 2,137 2,716 2,868 2,947 2,502 3,072 9,671 9,342 9,795 8,460 10,593 Salaries and Employee Benefits Occupancy and Equipment, net Data Processing Intangible Asset Amortization Office and Operations Other 2Q23 3Q23 4Q23 1Q24 2Q24

ORIGIN BANCORP, INC. _______ 9.6 10.0 10.5 10.7 10.7 10.1 10.3 10.5 10.6 10.5 Company Level Origin Bank Level 2Q23 3Q23 4Q23 1Q24 2Q24 11.2 11.6 12.0 12.2 12.3 11.7 12.0 11.9 12.1 12.2 Company Level Origin Bank Level 2Q23 3Q23 4Q23 1Q24 2Q24 23 CAPITAL 14.1 14.6 15.0 15.0 15.2 13.5 14.0 13.9 14.0 14.2 Company Level Origin Bank Level 2Q23 3Q23 4Q23 1Q24 2Q24 2Q24 Reported versus Capital Ratios incl. AOCI (%) ICap ICap Total Capital to Risk-Weighted Assets(20) (%) Tier 1 Capital to Risk-Weighted Assets(20) (%)Tier 1 Capital to Average Assets (Leverage Ratio)(20) (%) Please see slide 29 for all footnote references included above. 10.7 12.3 15.2 12.1 9.4 10.9 13.7 10.710.5 12.2 14.2 12.2 9.3 10.7 12.7 10.7 Company Level, Reported Company Level, incl. AOCI Bank Level, Reported Bank Level, incl. AOCI Tier 1 Leverage Ratio Tier 1 Capital Ratio Total Capital Ratio Common Equity Tier 1 Capital Ratio (21) (21) UNAUDITED

ORIGIN BANCORP, INC. _______ QTD YTD 2Q24 1Q24 2Q24 $ Impact EPS Impact (22) $ Impact EPS Impact (22) $ Impact EPS Impact (22) Notable interest income items: Interest income reversal on relationships impacted by questioned banker activity $ (1,206) $ (0.03) $ — $ — $ (1,206) $ (0.03) Notable provision expense items: Provision expense related to questioned banker activity (3,212) (0.08) — — (3,212) (0.08) Provision expense on relationships impacted by questioned banker activity (4,131) (0.10) — — (4,131) (0.10) Notable noninterest income items: MSR gain — — 410 0.01 410 0.01 Loss on sales of securities, net — — (403) (0.01) (403) (0.01) Gain on sub-debt repurchase 81 — — — 81 — Positive valuation adjustment on non-marketable equity securities 5,188 0.13 — — 5,188 0.13 Gain on bank property sale 800 0.02 — — 800 0.02 Notable noninterest expense items: Operating expense related to questioned banker activity (1,452) (0.04) — — (1,452) (0.04) Total notable items $ (3,932) (0.10) $ 7 — $ (3,925) (0.10) 24 DOLLARS IN THOUSANDS, EXCEPT PER SHARE AMOUNTS, UNAUDITED NOTABLE ITEMS

ORIGIN BANCORP, INC. _______ 2Q24 1Q24 Calculation of PTPP earnings: Net income $ 20,989 $ 22,632 Provision for credit losses 5,231 3,012 Income tax expense 5,747 6,227 PTPP earnings (non-GAAP) $ 31,967 $ 31,871 Calculation of PTPP ROAA: PTPP earnings $ 31,967 $ 31,871 Divided by number of days in the quarter 91 91 Multiplied by the number of days in the year 366 366 PTPP earnings, annualized $ 128,571 $ 128,184 Divided by total average assets $ 10,008,225 $ 9,861,236 ROAA (annualized) (GAAP) 0.84 % 0.92 % PTPP ROAA (annualized) (non-GAAP) 1.28 1.30 Calculation of tangible common equity to tangible assets: Total assets $ 9,947,182 $ 9,892,379 Goodwill (128,679) (128,679) Other intangible assets, net (41,177) (43,314) Tangible assets 9,777,326 9,720,386 Total common stockholders' equity $ 1,095,894 $ 1,078,853 Goodwill (128,679) (128,679) Other intangible assets, net (41,177) (43,314) Tangible common equity 926,038 906,860 Tangible common equity to tangible assets (non-GAAP) 9.47 % 9.33 % 25 DOLLARS IN THOUSANDS, UNAUDITED RECONCILIATION OF NON-GAAP FINANCIAL MEASURES

ORIGIN BANCORP, INC. _______ 2Q24 1Q24 Calculation of ROATCE: Net income $ 20,989 $ 22,632 Divided by number of days in the quarter 91 91 Multiplied by the number of days in the year 366 366 Annualized net income $ 84,417 $ 91,025 Total average stockholders' equity $ 1,084,269 $ 1,062,705 Average goodwill (128,679) (128,679) Average other intangible assets, net (42,563) (44,700) Average tangible common equity 913,027 889,326 ROATCE (annualized) (non-GAAP) 9.25 % 10.24 % 26 DOLLARS IN THOUSANDS, UNAUDITED RECONCILIATION OF NON-GAAP FINANCIAL MEASURES

ORIGIN BANCORP, INC. _______ Calculation of tangible book value per common share and adjusted tangible book value per common share: 2Q24 1Q24 4Q23 3Q23 2Q23 1Q23 4Q22 3Q22 Total common stockholders' equity $ 1,095,894 $ 1,078,853 $ 1,062,905 $ 998,945 $ 997,859 $ 992,587 $ 949,943 $ 907,024 Goodwill (128,679) (128,679) (128,679) (128,679) (128,679) (128,679) (128,679) (136,793) Other intangible assets, net (41,177) (43,314) (45,452) (42,460) (44,724) (47,277) (49,829) (52,384) Tangible common equity 926,038 906,860 888,774 827,806 824,456 816,631 771,435 717,847 Accumulated other comprehensive loss 127,184 124,909 121,023 172,729 152,879 138,481 159,875 175,233 Adjusted tangible common equity 1,053,222 1,031,769 1,009,797 1,000,535 977,335 955,112 931,310 893,080 Divided by common shares outstanding at period end 31,108,667 31,011,304 30,986,109 30,906,716 30,866,205 30,780,853 30,746,600 30,661,734 Book value per common share (GAAP) $ 35.23 $ 34.79 $ 34.30 $ 32.32 $ 32.33 $ 32.25 $ 30.90 $ 29.58 Tangible book value per common share (non-GAAP) 29.77 29.24 28.68 26.78 26.71 26.53 25.09 23.41 Adjusted tangible book value per common share (non-GAAP) 33.86 33.27 32.59 32.37 31.66 31.03 30.29 29.13 2Q22 1Q22 4Q21 3Q21 2Q21 1Q21 4Q20 3Q20 Total common stockholders' equity $ 646,373 $ 676,865 $ 730,211 $ 705,667 $ 688,235 $ 656,355 $ 647,150 $ 627,637 Goodwill (34,153) (34,153) (34,368) (26,741) (26,741) (26,741) (26,741) (26,741) Other intangible assets, net (15,900) (16,425) (16,962) (3,089) (3,283) (3,505) (3,739) (3,976) Tangible common equity 596,320 626,287 678,881 675,837 658,211 626,109 616,670 596,920 Accumulated other comprehensive loss (income) 115,979 65,890 (5,729) (11,872) (18,914) (12,185) (25,649) (21,998) Adjusted tangible common equity 712,299 692,177 673,152 663,965 639,297 613,924 591,021 574,922 Divided by common shares outstanding at period end 23,807,677 23,748,748 23,746,502 23,496,058 23,502,215 23,488,884 23,506,312 23,506,586 Book value per common share (GAAP) $ 27.15 $ 28.50 $ 30.75 $ 30.03 $ 29.28 $ 27.94 $ 27.53 $ 26.70 Tangible book value per common share (non-GAAP) 25.05 26.37 28.59 28.76 28.01 26.66 26.23 25.39 Adjusted tangible book value per common share (non-GAAP) 29.92 29.15 28.35 28.26 27.20 26.14 25.14 24.46 27 RECONCILIATION OF NON-GAAP FINANCIAL MEASURES Please see slide 29 for all footnote references included above. DOLLARS IN THOUSANDS, EXCEPT PER SHARE AMOUNTS, UNAUDITED

ORIGIN BANCORP, INC. _______ RECONCILIATION OF NON-GAAP FINANCIAL MEASURES DOLLARS IN THOUSANDS, UNAUDITED Calculation of core efficiency ratio: 2Q24 1Q24 4Q23 3Q23 2Q23 1Q23 4Q22 3Q22 Total noninterest expense $ 64,388 $ 58,707 $ 60,906 $ 58,663 $ 58,887 $ 56,760 $ 57,254 $ 56,241 Insurance and mortgage noninterest expense (8,402) (8,045) (8,581) (8,579) (9,156) (8,033) (8,031) (8,479) Adjusted total noninterest expense 55,986 50,662 52,325 50,084 49,731 48,727 49,223 47,762 Net interest income 73,890 73,323 72,989 74,130 75,291 77,147 84,749 78,523 Insurance and mortgage net interest income (2,407) (2,795) (2,294) (2,120) (1,574) (1,493) (1,376) (1,208) Total noninterest income 22,465 17,255 8,196 18,119 15,636 16,384 13,429 13,723 Insurance and mortgage noninterest income (8,543) (10,123) (4,727) (7,335) (7,587) (8,792) (6,255) (4,737) Adjusted total revenue 85,405 77,660 74,164 82,794 81,766 83,246 90,547 86,301 Efficiency ratio (GAAP) 66.82 % 64.81 % 75.02 % 63.59 % 64.76 % 60.69 % 58.32 % 60.97 % Core efficiency ratio (non-GAAP) 65.55 65.24 70.55 60.49 60.82 58.53 54.36 55.34 2Q22 1Q22 4Q21 3Q21 2Q21 1Q21 4Q20 3Q20 Total noninterest expense $ 44,150 $ 42,774 $ 40,346 $ 39,165 $ 37,832 $ 39,436 $ 38,884 $ 38,734 Insurance and mortgage noninterest expense (8,397) (8,626) (6,580) (6,688) (6,964) (7,252) (7,195) (7,746) Adjusted total noninterest expense 35,753 34,148 33,766 32,477 30,868 32,184 31,689 30,988 Net interest income 59,504 52,502 54,180 52,541 54,292 55,239 51,819 50,617 Insurance and mortgage net interest income (1,082) (875) (946) (1,048) (979) (1,003) (1,236) (1,125) Total noninterest income 14,216 15,906 16,701 15,923 12,438 17,131 15,381 18,051 Insurance and mortgage noninterest income (8,047) (10,552) (5,683) (6,179) (5,815) (8,348) (9,326) (12,741) Adjusted total revenue 64,591 56,981 64,252 61,237 59,936 63,019 56,638 54,802 Efficiency ratio (GAAP) 59.89 % 62.53 % 56.92 % 57.21 % 56.69 % 54.49 % 57.86 % 56.41 % Core efficiency ratio (non-GAAP) 55.35 59.93 52.55 53.03 51.50 51.07 55.95 56.55 28

ORIGIN BANCORP, INC. _______ 29 PRESENTATION NOTES (1) Does not include wholesale or mortgage warehouse deposits. (2) Excludes MW LOC. (3) New Fort Walton Beach, Florida loan production office opened in 1Q24. (4) As used in this presentation, PTPP earnings, PTPP ROAA, tangible book value per common share, adjusted tangible book value per common share, tangible common equity, adjusted tangible common equity, tangible common equity to tangible assets, ROATCE, and core efficiency ratio are either non-GAAP financial measures or use a non-GAAP contributor in the formula. For a reconciliation of these alternative financial measures to their comparable GAAP measures, see slides 25-28 of this presentation. (5) Total LHFI, adjusted excludes MW LOC for all periods presented. (6) Origin Bancorp, Inc. and KBW Nasdaq cumulative total shareholder return assumes $100 invested on December 31, 1996, and any dividends are reinvested. Data for Origin Bancorp, Inc. cumulative total shareholder return prior to May 9, 2018, is based upon private stock transactions and is not reflective of open market trades. (7) Data obtained from The United States Census Bureau (census.gov). Count is as of most recent practicable date. (8) Year-to-date periods ended December 31, 2020 and 2021, exclude PPP loans. (9) Does not include loans held for sale. (10) The ALCL to total LHFI, adjusted is calculated by excluding the ALCL for MW LOC from the total LHFI ALCL in the numerator and excluding the MW LOC from the LHFI in the denominator. Due to their low-risk profile, MW LOC require a disproportionately low allocation of the ALCL. (11) The sensitivity analysis is based on loans exceeding $2.5 million. (12) Represents an interest rate sensitivity test for CRE office loans over $2.5 million using interest rate assumptions increased to 8.6% for 2024 maturities, 8.1% for 2025 maturities, 6.9% for 2026 maturities, 6.10% for 2027 maturities and 5.6% for 2028+ maturities, based upon federal open market committee projections at March 20, 2024. (13) Represents the weighted average loan to value based upon an increase to a 10% stress capitalization rate on loans exceeding $2.5 million within the CRE non-owner occupied office portfolio. (14) The accumulated other comprehensive loss primarily represents the unrealized loss, net of tax benefit, of available for sale securities and is a component of equity. (15) For purposes of this classification, all reciprocal deposits are classified as commercial deposits. (16) PAA refers to purchase accounting adjustments. (17) Net interest income excl. MW LOC, adjusted, represents net interest income less interest income on MW LOC, excluding PAA net accretion/amortization for the 2Q23 period. (18) Adjusted NIM-FTE is calculated by removing the net purchase accounting accretion or amortization from the net interest income. (19) Mortgage banking revenue for 1Q24 and 4Q23 was adjusted for the $410,000 gain on sale and $1.8 million impairment, respectively, on the MSR portfolio. (20) June 30, 2024, dollars and ratios are estimated. (21) Capital ratios including AOCI are calculated by including the accumulated other comprehensive loss in the equity used in the numerator of the respective ratios and including the primarily negative fair value adjustments on the available for sale portfolio in the total risk-weighted assets used in the denominator of the ratio. (22) The diluted EPS impact is calculated using a 21% effective tax rate. The total of the diluted EPS impact of each individual line item may not equal the calculated diluted EPS impact on the total notable items due to rounding.