O'Byrne () is an Irish surname. The O'Byrne family were descendants of Bran mac Máelmórda, King of Leinster.
Notable people with the surname include:
Brían F. O'Byrne (b. 1967), Irish actor Bryan O'Byrne (1931–2009), American actor Cathal O'Byrne (1867–1957), Irish singer, poet and writer Charles J. O'Byrne (b. 1959), American lawyer David O'Byrne (b. 1969), Australian trade unionist and politician Emmett O'Byrne (b. 1973), Irish historian Estella Armstrong O'Byrne (1891–1987), American civic leader and anti-communist Fergus O'Byrne, Irish-Canadian folk musician Fiach McHugh O'Byrne (1534–1597), Gaelic chieftain famed for his resistance to English rule in Ireland Felim McFiach O'Byrne (d.1630), Gaelic chieftain Gay Byrne (b. 1934), Irish radio and television presenter John O'Byrne (1884–1954), Attorney General of the Irish Free State Justin O'Byrne (1912–1993), Australian politician Michelle O'Byrne (b. 1968), member of the Tasmanian House of Assembly Patrick O'Byrne (pianist) (b. 1954), New Zealand pianist Patrick O'Byrne (politician) (1870–1944), Irish politician Ryan O'Byrne (b. 1984), Canadian ice hockey player William O'Byrne (1908–1951), English cricketer William Richard O'Byrne (1823–1896), Irish biographer
See also O'Byrne Cup, in Gaelic football Byrne