Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the following Registration Statements:

(i)  Registration Statement (Form S-3 Nos. 333-70111, 333-30394, 333‑62434, 333-126058, 333-228887 and 333-223209) of SL Green Realty Corp. and the related Prospectuses;

(ii)  Registration Statement (Form S-8 Nos. 333-61555, 333-87485, 333-89964, 333-127014, 333-143721, 333-189362 and 333-212108) pertaining to the Stock Option and Incentive Plans of SL Green Realty Corp., and

(iii) Registration Statement (Form S-8 No. 333-148973) pertaining to the 2008 Employee Stock Purchase Plan of SL Green Realty Corp.,

of our reports dated February 28, 2020, with respect to the consolidated financial statements of SL Green Realty Corp and the effectiveness of internal control over financial reporting of SL Green Realty Corp., included in this Annual Report (Form 10-K) of SL Green Realty Corp for the year ended December 31, 2019.

/s/ Ernst & Young LLP

New York, New York

February 28, 2020