Frank O'Brien

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