William John Neeson was born on 7 June 1952 in Ballymena, County Antrim, the son of primary school caretaker Bernard "Barney" Neeson and cook Katherine "Kitty" Neeson (née Brown). His mother was born and raised in Waterford in the south-east of Ireland. Brought up Catholic, he was named Liam after a local priest. He has three sisters, Elizabeth, Bernadette, and Rosaleen. He attended St Patrick's College, Ballymena, from 1963 to 1967, and later recalled that his love of drama began there.
He said that growing up as a Catholic in a predominantly Protestant town made him cautious, and once said he felt like a "second-class citizen" there, but has also said he was never made to feel "inferior or even different" at the town's predominantly Protestant technical college. "It would be colourful to imagine I had a rebellious, uproarious Irish background," he has said, "but the facts were much greyer. Irish, yes. But all that nationalistic stuff, crying into your Guinness and singing rebel songs—that was never my scene." He has described himself as "out of touch" with the politics and history of Northern Ireland until becoming aware of protests by fellow students after Bloody Sunday, a massacre in Derry in 1972 during the Troubles, which encouraged him to learn more local history. In a 2009 interview, he said, "I never stop thinking about [the Troubles]. I've known guys and girls who have been perpetrators of violence and victims. Protestants and Catholics. It's part of my DNA."
At age nine, Neeson began boxing lessons at the All Saints Youth Club, and went on to win a number of regional titles before quitting at 17. He acted in school productions during his teens. His interest in acting and decision to become an actor were also influenced by Ian Paisley, founder of the Democratic Unionist Party (DUP), into whose Free Presbyterian Church of Ulster he sneaked. He said, "[Paisley] had a magnificent presence and it was incredible to watch him just Bible-thumping away... it was acting, but it was also great acting and stirring too." In 1971, he joined a physics and computer science course at Queen's University Belfast before leaving to work for the Guinness Brewery. At Queen's, he discovered a talent for football and was spotted by Seán Thomas at Bohemian FC. There was a club trial in Dublin and Neeson played one game as a substitute against Shamrock Rovers FC, but was not offered a contract.
