Michael S. Sullivan (April 2, 1876 – May 22, 1929) was a civil engineer, surveyor and politician in Newfoundland. He represented Placentia and St. Mary's from 1904 to 1909 as a Liberal and from 1919 to 1928 as a Liberal-Labour-Progressive and from 1928 to 1929 as a Liberal-Conservative Progressive in the Newfoundland House of Assembly.