Ephraim Knight Smart (September 3, 1813 – September 29, 1872) was a United States Representative from Maine.
Smart was born in Prospect (now Searsport) on September 3, 1813. He attended the common schools, completed preparatory studies under private tutors and attended Maine Wesleyan Seminary. He studied law, was admitted to the bar and commenced practice in Camden.
Smart was appointed postmaster in Camden in 1838. He was elected a member of the Maine State Senate. He was appointed aide-de-camp with the rank of lieutenant colonel on the staff of Governor Fairfield in 1842. Smart moved to Missouri in 1843 and continued the practice of his profession. He returned to Camden the following year and resumed the practice of law,and was again appointed postmaster. He was elected as a Democrat to the Thirtieth Congress (March 4, 1847 – March 3, 1849) and to the Thirty-second Congress (March 4, 1851 – March 3, 1853).
After retirement, served as collector of customs at Belfast 1853-1858. He established the Maine Free Press in 1854, and served as editor for three years. He was elected a member of the Maine House of Representatives in 1858, and was an unsuccessful candidate for Governor of Maine in 1860. He again served in the State Senate, and moved to Biddeford and established the Maine Democrat.
Smart died in Camden on September 29, 1872. He is interred at Mountain Street Cemetery.