Michael Brennan (1884 – 6 October 1970) was an Irish politician who served as a Teachta Dála (TD) for fifteen years for the Roscommon constituency.
A farmer, Brennan was first elected as an independent TD to the 5th Dáil at the June 1927 general election and returned to the 6th Dail at the September 1927 general election.
After losing his seat at the 1932 general election, Brennan joined Cumann na nGaedheal and was returned to the 8th Dáil at the 1933 general election. He was re-elected at the 1937 general election to the 9th Dáil and at the 1938 general election to the 10th Dáil. He lost his seat at the 1943 general election, and stood again unsuccessfully as a Fine Gael candidate at the 1944 general election.
He stood as an independent candidate at the 1948 general election, and for Fine Gael at the 1951 general election, but was unsuccessful on both occasions.