Martin O'Brien

Martin O'Brien may refer to:


 * Martin O'Brien (artist), British performance artist
 * Martin O'Brien (journalist), Irish journalist
 * Martin O'Brien (footballer) (1875–1946), Australian rules footballer
 * Martin O'Brien (humanitarian) (born 1964), human rights activist and charity administrator in Northern Ireland
 * Martin O'Brien (hurler) (1885–1958), Irish hurler