Daniel Darwin Pratt (October 26, 1813 – June 17, 1877) was a United States Senator from Indiana. Born in Palermo, Maine, he moved to New York with his parents, who settled in Fenner. He attended the public schools and Cazenovia Seminary, and graduated from Hamilton College in 1831. He moved to Indiana in 1832 and taught school; in 1834 he settled in Indianapolis and was employed in the office of the Secretary of State.