Exhibit 23 to 2009 10-K

Consent of Independent Registered Public Accounting Firm

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

• Form S-8 No. 333-66992 pertaining to the Geneva Technology Limited Unapproved Share Option Scheme 1998,

• Form S-8 No. 333-69633 pertaining to the Convergys Corporation Employee Stock Purchase Plan,

• Form S-8 No. 333-86137 pertaining to the Convergys Corporation Canadian Employee Share Purchase Plan,

• Form S-8 No. 333-96727 pertaining to the Convergys Corporation 1998 Long Term Incentive Plan,

• Form S-8 No. 333-96729 pertaining to the Convergys Corporation Deferred Compensation and LTIP Award Deferral Plan for Non-Employee Directors,

• Form S-8 No. 333-96733 pertaining to the Convergys Corporation Retirement and Savings Plan,

• Form S-3 No. 333-150856 pertaining to Convergys Corporation’s shelf registration statement for the possible registration of debt securities; and

• Form S-4 No. 333-161586 pertaining to Convergys Corporation’s registration of $125 million of junior subordinated convertible debentures and related prospectus for the registration of junior subordinated convertible debentures and common shares.

of our reports dated February 26, 2010, with respect to the consolidated financial statements and schedule of Convergys Corporation and the effectiveness of internal control over financial reporting of Convergys Corporation, included in this Annual Report (Form 10-K) for the year ended December 31, 2009.

/s/ Ernst & Young LLP

Cincinnati, Ohio

February 26, 2010