Exhibit 22.1

List of Subsidiary Guarantors and Issuers

of Guaranteed Securities

As of March 31, 2020, the following entities guarantee the notes issued by ONEOK, Inc. (the “ONEOK Notes”) and ONEOK Partners, L.P. (the “ONEOK Partners Notes”).

Entity	Jurisdiction of Incorporation or Organization	ONEOK Notes	ONEOK Partners Notes
ONEOK, Inc.	Oklahoma	Issuer	Guarantor
ONEOK Partners, L.P.	Delaware	Guarantor	Issuer
ONEOK Partners Intermediate Limited Partnership	Delaware	Guarantor	Guarantor

As of March 31, 2020, the ONEOK Notes consisted of the following securities:

Issued under the Indenture dated as of September 24, 1998

6-7/8% Debentures due 2028

Issued under the Indenture dated as of December 28, 2001

6.00% Notes due 2035

Issued under the Indenture dated as of January 26, 2012

4.25% Notes due 2022

7.50% Notes due 2023

2.75% Notes due 2024

2.200% Notes due 2025

4.55% Notes due 2028

4.35% Notes due 2029

3.40% Notes due 2029

3.100% Notes due 2030

5.20% Notes due 2048

4.45% Notes due 2049

4.500% Notes due 2050

Issued under the Indenture dated as of July 13, 2017

4.000% Notes due 2027

4.950% Notes due 2047

As of March 31, 2020, the ONEOK Partners Notes consisted of the following securities:

Issued under the Indenture dated as of September 25, 2006

3.375% Senior Notes due 2022

5.000% Senior Notes due 2023

4.90% Senior Notes due 2025

6.65% Senior Notes due 2036

6.85% Senior Notes due 2037

6.125% Senior Notes due 2041

6.200% Senior Notes due 2043