Crean was born in Hamilton, Victoria. He attended Melbourne High School and the University of Melbourne, and subsequently worked as a tax accountant. Crean was elected to the Victorian Legislative Assembly in 1945. He lost his seat in 1947 and reclaimed it in 1949, but quit state politics two years later to stand at the 1951 federal election. Crean spent the first 21 years of his career in federal politics in opposition, albeit as a frontbencher for most of that time. He became Treasurer after the 1972 election, but economic uncertainty and factional considerations meant he was replaced by Jim Cairns after two years. He was instead appointed Minister for Overseas Trade. Crean held that position until the government's dismissal in 1975, and for its final six months was also deputy prime minister, replacing Cairns when he became embroiled in the Khemlani affair. He left politics at the 1977 election.