Niall O'Brien

Niall O'Brien may refer to:


 * Niall O'Brien (actor) (1946–2009), Irish actor
 * Niall O'Brien (cricketer) (born 1981), Irish cricketer
 * Niall O'Brien (hurler) (born 1994), Irish hurler
 * Niall O'Brien (priest) (1939–2004), Irish Columban missionary priest