Born in Bandon, County Cork, Ireland, his original name was Graham Walker. He was brought up in County Cork in Ireland. His father, Billy Walker, was a Guinness representative. His mother, Rhoda Walker, was a leading figure in the Mothers' Union. His family was Protestant in a 98% Roman Catholic area.
Graham hoped to become a journalist but failed to get a place at journalism school. He went to University College Cork to study English and French but dropped out at the end of his first year when he became disillusioned.
He travelled to the USA and joined a hippie commune in San Francisco. He was briefly engaged to an American girl but it was broken off when he came to recognise for the first time that he was gay. He returned to Cork and completed his degree.
Graham moved to London where he joined the Central School of Speech and Drama. He changed his name because Equity already had a Graham Walker. "Norton" is his great-grandmother's maiden name. He found little acting work, and his best role was in Shadow of a Gun Man at the Liverpool Playhouse.
He worked as a waiter and a barman, until his late 20s. He became notorious for his camp bitchiness to customers. This led to ideas of comic performance.
Graham tried a few routines in a friend's bar and then in 1991 he wrote himself the show Mother Teresa of Calcutta's Grand Farewell Tour and took it to the Edinburgh Festival fringe. He staged his successful one-man shows at the Edinburgh Festival from 1992 to 1997, including The Karen Carpenter Bar and Grill. Graham began to make his name nationally when Charlie's Angels Go To Hell transferred to London. He was nominated for the Perrier Award in 1997.
Also in 1997 he had a few guest appearances in the minor role of the hyperactive Father Noel in the successful sitcom television series Father Ted.
Channel 5 television also gave him a deal in 1997. He stood in for the chatshow anchor man Jack Docherty and he showed his forte. As a result he was named Best Newcomer at the 1997 British Comedy Awards. Channel 5 then gave him his first television series Bring Me The Head of Light Entertainment.
Graham received a Comedy Award for the time he was stand-in for Gay Byrne on Ireland's Late, Late Show. In 1999 he started his series So, Graham Norton with Channel 4 television. He was named Gay Entertainer of The Year at the 1999 Gaytime TV Awards.
On May 15, 2000 he received the Bafta award for Best entertainment performance for his role in So Graham Norton on Channel 4 television. By this time the show was being made by his own production company.
He and his boyfriend, the American television researcher Scott Michaels, lived together from 1995 until they split up in January 2001.
On May 13, 2001 Graham Norton received the Bafta award for Best Entertainment Performance for his role in So Graham Norton on Channel 4 television for the second year running. The programme was also given the Best Entertainment Programme or Series award.
Also in 2001 the BBC tried to lure Graham Norton with an offer worth more than £5 million, but he turned it down because he feared that he would have to tone down his antics. In August of the same year he returned to the Edinburgh Festival to host the final of the So You Think You're Funny? competition.