Martin Brennan

• Martin Brennan (Irish politician), Irish medical practitioner and Fianna Fáil politician, TD from 1938 to 1948
• Martin Brennan (engineer), computer engineer who worked for Sinclair Research and Atari
• Martin A. Brennan, U.S. Representative from Illinois
• Martin Brennan (hurler), Irish retired sportsman
• Martin Stanislaus Brennan, American Roman Catholic priest and scientist
• Martin Brennan (footballer), English footballer
• Martin Brennan (character), a fictional character created by the comedian Steve Coogan