Avista (AVA) 11-K Annual report of employee stock purchases

Exhibit 23

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in Registration Statement No. 333-33790 on Form S-8 of our report dated May 29, 2020 appearing in this Annual Report on Form 11-K of Investment and Employee Stock Ownership Plan of Avista Corporation for the year ended December 31, 2019.

/s/ CliftonLarsonAllen LLP

Charlotte, North Carolina

May 29, 2020