EXHIBIT 15

ACKNOWLEDGMENT OF ERNST & YOUNG LLP,

INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

May 3, 2019

The Board of Directors and Shareholders of KeyCorp

We are aware of the incorporation by reference in the following Registration Statements (including all amendments thereto) of KeyCorp:

Form S-3 No. 333-55959        

Form S-3 No. 333-59175        

Form S-3 No. 333-64601        

Form S-3 No. 333-76619        

Form S-3 No. 333-218629        

Form S-8 No. 333-49609        

Form S-8 No. 333-70669                                

Form S-8 No. 333-107074        

Form S-8 No. 333-107075        

Form S-8 No. 333-107076                

Form S-8 No. 333-112225        

Form S-8 No. 333-116120        

Form S-8 No. 333-167093        

Form S-8 No. 333-188703

Form S-8 No. 333-208272

of our review report dated May 3, 2019 relating to the unaudited consolidated interim financial statements of KeyCorp that are included in its Form 10-Q for the quarter ended March 31, 2019.

Ernst & Young

Cleveland, Ohio