Namesakes
Niall Noígíallach
(m) ?-c. 400 
Irish Kings 368-395
Niall Frossach
(m) ?-c. 770
Irish Kings 763-770
Niall Caille
(m) ?-846
Irish Kings 833-846
Niall Glúndub
(m) 870-919
Irish Kings 916-919
Niall Brigant
(m)
Fictional Characters from Books 2001 The Southern Vampire Mysteries
Fictional Characters from Television 2008 True Blood
Niall Horan
(m) 1993-
Notable Musicians
Niall McGinn
(m) 1987-
Notable Athletes (soccer)
Niall O'Brien
(m) 1981-
Notable Athletes (cricket)
Niall Tóibín
(m) 1929-2019
Notable Actors and Entertainers (actor/comedian)