Thomas Martin Brennan (born October 30, 1952) is a former pitcher in Major League Baseball.

He pitched from 1981 to 1985 for the Cleveland Indians, Chicago White Sox and Los Angeles Dodgers.

Brennan played college baseball for Lewis University in Romeoville, Illinois, where he helped the Flyers win the 1974 NAIA World Series.

Brennan was inducted into the National College Baseball Hall of Fame in 2021.

This biographical article relating to an American baseball pitcher born in the 1950s is a stub.