Thomas Kirker (1760 - February 20, 1837) was an Democratic-Republican politician from Ohio. He served as the 2nd Governor of Ohio.

Kirker was born in County Tyrone , Ireland. He moved with his father to Lancaster, Pennsylvania in 1779. He moved with his new wife to Kentucky in 1790 and then Liberty Township , Adams County, Ohio three years later. He served in the first Ohio House of Representatives in 1803 and then in the Ohio State Senate from 1804-1815. While serving as Speaker of the Senate, Kirker became Governor upon the resignation of Edward Tiffin to take a seat in the U.S. Senate. Kirker's term was extended through the 1807-1808 meeting of the Assembly due to the disqualification of Return J. Meigs, Jr. who had won the 1807 election to the governorship but had been disqualified by the Assembly as he had not met the residency requirements. Kirker ran for re-election in 1808, but lost badly to Samuel H. Huntington. Kirker later returned to the Assembly, serving in the House of Representatives from 1816-1817 and in the State Senate from 1821-1825.