EXHIBIT 99.15

CONSENT OF EXPERT

Reference is made to the Annual Report on Form 40-F (the Form
40-F) of Cameco Corporation (the Corporation) to be filed with the United States Securities and Exchange Commission pursuant to the United States Securities Exchange Act of 1934, as amended.

I hereby consent to reference to my name and my involvement in the preparation of, or supervision of the preparation of, scientific and
technical information in the following instances:



| | (a) | under the headings Operations and Projects  Uranium Operating Properties  McArthur River/Key Lake, Operations and Projects  Uranium Operating Properties  Cigar Lake,
Mineral Reserves and Resources  and Governance  Interest of Experts in the Corporations Annual Information Form for the year ended December 31, 2016 dated March 23, 2017 for the McArthur River/Key Lake
and Cigar Lake properties; and
| | --- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | (b) | under the headings Our Operations and Projects  Uranium Operating Properties  McArthur River mine/Key Lake mill, Our Operations and Projects  Uranium Operating Properties  Cigar
Lake and Mineral Reserves and Resources in Managements Discussion and Analysis of Financial Condition and Results of Operation for the year ended December 31, 2016 dated February 9, 2017 for the McArthur River/Key
Lake and Cigar Lake properties,
| | --- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

(collectively the Technical Information) in the Form
40-F, and to the inclusion and incorporation by reference of information derived from the Technical Information in the Form 40-F.

I also hereby consent to the incorporation by reference of such Technical Information in the registration statements (Nos. 333-11736, 333-6180 and 333-139165) on Form S-8 for the Cameco Corporation Stock Option Plan,
registration statement (No. 333-196422) on Form S-8 for the Cameco Corporation Employee Share Ownership Plan and registration statement (No. 333-200678) on Form F-10.

Sincerely,



|                           |  |                                                                 
|-------------------------- |  | ----------------------------------------------------------------
|/s/ Leslie (Les) D.
Yesnik
|Name:                      |  | Leslie (Les) D. Yesnik, P. Eng.                                 
|Title:                     |  | General Manager, McArthur River and Key Lake, Cameco Corporation

Date: March 23, 2017