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.
- The New York Civil List  compiled by Franklin Benjamin Hough (pages 137 and 145; Weed, Parsons and Co., 1858)
- Pen and Ink Portraits of the Senators, Assemblymen, and State Officers of New York  by G. W. Bungay (1857; pg. 61)
- LAW REPORTS; SURROGATE's COURT; WILLS OFFERED FOR PROBATE  in NYT on February 4, 1859
- Mark Spencer  at Ancestry.com