CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
We have issued our reports dated February 23, 2018 with respect to the consolidated financial statements, financial highlights, Schedule 12-14, and the Senior Securities table of Main Street Capital Corporation for the year ended December 31, 2017 contained in this Registration Statement and Prospectus. We consent to the use of the aforementioned reports in this Registration Statement and Prospectus and to the use of our name as it appears under the captions "Senior Securities", "Selected Financial Data" and "Independent Registered Public Accounting Firm."
/s/ GRANT THORNTON LLP
Houston,
Texas
March 7, 2018