Michael Terrance O'Brien (10 August 1893 – 21 September 1940) was an Irish footballer and coach whose career took him to at least 17 different clubs. A well built six footer, O'Brien was highly regarded as a centre-half. O'Brien was a dual international and played for both Ireland teams – the IFA XI and the FAI XI. In April 1927 O'Brien made his debut for the FAI XI, four days after he made his last appearance for the IFA XI. During the 1930s O'Brien managed both Queens Park Rangers and Ipswich Town.