Son of local butcher John Myers and wife Betty, Allan was schooled at Dunkeld, then Monivae College in Hamilton, and Melbourne University, where he studied law. Allan studied at Oxford and taught at Osgoode Hall Law School in Toronto, Canada. A barrister in 1975, he was appointed a Queen's Counsel in 1986. In 2004 he was appointed President of Trustees of the National Gallery of Victoria.