Thomson Mason (14 August 1733 – 26 February 1785) was an American lawyer, planter and jurist. A younger brother of George Mason IV, United States patriot, statesman, and delegate from Virginia to the U.S. Constitutional Convention, Thomson Mason would father Stevens Thomson Mason (who after service in the American Revolutionary War followed his father's career into law and politics and eventually become a U.S. Senator from Virginia), and was the great-grandfather of Stevens T. Mason, first Governor of Michigan.