Zenas Clark (1795–1864) was an American politician from New York.
In 1816, he co-founded the first newspaper in Potsdam, the Potsdam Gazette.
He was Supervisor of the Town of Potsdam from 1830 to 1834.
He was a member of the New York State Assembly (St. Lawrence Co.) in 1840 and 1841.
He was a member of the New York State Senate (15th D.) from 1854 to 1857, sitting in the 77th, 78th, 79th and 80th New York State Legislatures. He resigned his seat on February 13, 1857, due to ill health.
He was buried at the Bayside Cemetery in Potsdam.