Lynott was born in Hallam Hospital (now Sandwell General Hospital) in West Bromwich (then in Staffordshire), England, some say the son of a black Brazilian father, named Parris, and an Irish Catholic mother, Philomena (aka Phyllis) Lynott, whose surname he took. His father left his mother just three weeks after he was born and returned to his native Brazil. Philip was brought up in Crumlin, Dublin by his grandmother, Sarah. His parents reportedly kept in touch for a number of years after his birth, and Philip did meet his father in the late 1970s.
In the mid-1960s, Lynott began singing in his first band, the Black Eagles. It was around this time that he befriended Brian Downey. He formed Thin Lizzy around 1969 in Dublin after a short stint in Skid Row with Gary Moore. Lynott was the main songwriter for Thin Lizzy, as well as the lead singer and bassist. Lynott was half black, and was inspired by Jimi Hendrix as an example of how a black man could be successful fronting a hard rock band. Their first top ten hit was in 1973 with the traditional Irish song "Whiskey In The Jar".