Jackman was born in Pymble, Sydney, New South Wales, the youngest of five children of English-born parents Chris Jackman and Grace Watson. His mother left the family when he was eight years old, and he remained behind with his father, an accountant with a degree from Cambridge, and siblings.

Jackman attended Pymble Public School and Knox Grammar School, an all-boys school, where he starred in the musical My Fair Lady in 1985, directed by the headmaster, Dr. Ian Paterson. Jackman was School Captain in 1986 and his favourite subject was Ancient History. The following year he spent a gap year working at Uppingham School in England. Upon his return to Australia he worked at a Shell station in Wahroonga and worked as a part-time clown for children's parties while studying at the University of Technology, Sydney. In 1989, Jackman participated in a Christian workcamp on Hasst's Bluff and Areyonga Aboriginal land in the Western Desert in Central Australia. He then graduated with a BA