Thomas O'Brien

• Thomas Alexander O'Brien
• Thomas C. O'Brien
• Thomas D. O'Brien
• Thomas J. O'Brien (Illinois politician)
• Thomas J. O'Brien (Massachusetts politician)
• Thomas J. O'Brien (Michigan politician)
• Thomas J. O'Brien (bishop)
• Thomas O'Brien (bishop)
• Thomas O'Brien (footballer)
• Thomas O'Brien (interior designer)
• Thomas P. O'Brien
• Thomas W. O'Brien
• Tom O'Brien (American football)
• Tom O'Brien (actor)
• Tom O'Brien (footballer, born 1889)
• Tom O'Brien (footballer, born 1904)
• Tom O'Brien (jockey)
• Tom O'Brien (outfielder)
• Tom O'Brien (second baseman)
• Tom O'Brien (swindler)
• Tom O'Brien (trade unionist)
• Tommy O'Brien