Irineu is the Portuguese version of the male given name Irenaeus.
Notable people with the name include:
Irineu Esteve Altimiras (born 1996), Andorran cross-country skier Irineu Calixto Couto (born 1983), Brazilian footballer Irineu Gassen (born 1942), Brazilian bishop Irineu Evangelista de Sousa (1813 – 1889), Brazilian businessman and politician Victor Irineu de Souza (born 1989), Brazilian footballer Irineu Sílvio Wilges (1936 – 2022), Brazilian bishop