Frank O'Brien may refer to: Frank O'Brien (politician), Pennsylvania politician Frank O'Brien (footballer) (1900–1986), Australian rules footballer Frank O'Brien (rugby union) (1910–1984), Australian rugby union player Frank P. O'Brien, mayor of Birmingham, Alabama Dink O'Brien (Frank Aloysius O'Brien, 1894–1971), baseball player
See also Francis O'Brien (disambiguation)