FIDUS INVESTMENT Corp

2025 Annual Meeting of Stockholders

This proxy statement is furnished in connection with the solicitation of proxies by the Board of Directors of Fidus Investment Corporation (the “Company,” “Fidus,” “we,” “us” or “our”) for use at our 2025 Annual Meeting of Stockholders to be held on June 11, 2025, at 8:30 a.m. (Central Time) at 1603 Orrington Avenue, Suite 1005, Evanston, Illinois, 60201 and at any adjournments thereof (the “Annual Meeting”). The Notice of Annual Meeting, this proxy statement, the accompanying proxy card and our Annual Report on Form

10-K

for the fiscal year ended December 31, 2024 (the “Annual Report”) are first being sent to stockholders on or about March 27, 2025.

We encourage you to vote your shares, either by voting in person at the Annual Meeting or by granting a proxy (i.e., authorizing someone else to vote your shares). If you vote by mail, Internet or telephone as described in the instructions on the proxy card or voting instruction form, and we receive your vote in time for the Annual Meeting, the persons named as proxies will vote the shares registered directly in your name in the manner that you specified.

If you give no instructions on the proxy card, the shares covered by the proxy card will be voted FOR the election of the director nominees and FOR the other matters listed in the accompanying Notice of Annual Meeting of Stockholders.

YOUR VOTE IS IMPORTANT. WHETHER OR NOT YOU PLAN TO ATTEND THE ANNUAL MEETING, PLEASE PROMPTLY VOTE YOUR SHARES EITHER BY MAIL, INTERNET OR TELEPHONE.

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE ANNUAL MEETING TO BE HELD ON JUNE 11, 2025:

The Notice of Annual Meeting, proxy statement, and our Annual Report are available at the following Internet address:

www.viewproxy.com/fidusinv/2025/

.