Early life

Gibson was born in Peekskill, New York, the sixth of eleven children. He is the second son of Hutton Gibson and Irish-born Anne Reilly Gibson. His paternal grandmother was the Australian opera soprano, Eva Mylott (1875–1920).One of Gibson's younger brothers, Donal, is also an actor. Gibson's first name comes from a 5th century Irish Saint, Mel, founder of the diocese of Ardagh which contains most of his mother's native County, while his second name, Columcille, is also linked to an Irish saint. Columcille is also the name of the parish in County Longford where Anne Reilly was born and raised. Because of his mother, Mel Gibson holds dual citizenship in America and the Republic of Ireland.

Hutton Gibson relocated his family to Sydney, Australia in 1968, after winning $145,000 in a work related injury lawsuit against New York Central on February 14, 1968. The family moved when Gibson was twelve. The move to Hutton's mother's native Australia was for economic reasons and because he thought the Australian military would reject his oldest son for the Vietnam War draft.

Gibson was educated by Christian Brothers at St. Leo's Catholic College in Wahroonga, New South Wales during his High School years.