Mark Spencer (July 5, 1787 – January 28, 1859) was an American merchant and politician from New York.
He was the son of Mark Spencer (1738–1815) and Huldah Parmelee (Collins) Spencer.
He was a member of the New York State Senate (5th D.) from 1854 to 1857, sitting in the 77th, 78th, 79th and 80th New York State Legislatures. On January 24, 1857, he was elected President pro tempore of the State Senate.