П. O. (or Pi O, born 1951) is a Greek-Australian, working class, anarchist poet. Born in Katerini, Greece, П. O. came to Australia with his family around 1954. After time in Bonegilla Migrant Reception and Training Centre, the family moved to the Melbourne suburb of Fitzroy. His first published book, Fitzroy Brothel, was released in 1974. From 1978 to 1983, he was involved in producing the radical poetry magazine 925. After the publication of several more collections, his 740-page epic poem 24hrs was published in 1996 by Collective Effort Press.