Oscar F. Bartlett, M.D., (October 2, 1823 – November 1911) was an American teacher, farm laborer, physician, and politician from Cayuga County, New York. He served as a Union Army Surgeon during the American Civil War and represented Walworth County for two years each in the Wisconsin State Senate and Wisconsin State Assembly. He was a member of the Free Soil Party until its merger to create the Republican Party, and was thereafter a liberal Republican.