South Australian born Shaun Micallef studied law at Adelaide University and was heavily involved in the University Footlights drama group. He worked as a solicitor until 1993 when, encouraged by his mentor Gary McCaffrie, he decided to leave law and try his luck as a comedy writer, moving to Melbourne to write for Full Frontal and later Jimeon. He soon began appearing on the shows and became co-producer of Full Frontal as well as writing for The Big Gig.
In 1998, Shaun debuted on the ABC with The Micallef Programme. A year later came The Micallef Pogram. In 2000, Shaun left comedy aside when he took on his first major drama role. As Warwick Munro, he romanced Sigrid Thornton and Australian viewers in the final series of SeaChange. The following year, he filmed the final series of The Micallef Program and hosted the 2001 TV Week Logie Awards. In 2002, aside writing and filming Welcher & Welcher – Shaun wrote the telemovie Blackjack (in conjunction with Gary McCaffrie) and was cast in Tony Martin's debut feature Bad Eggs as well as The Honourable Wally Norman, directed by Ted Emery.
2003 saw the emergence and premature death of Micallef Tonight, Shaun's hysterical and off-beat comedy variety show, which featured some of the world's biggest stars in entertainment, media and politics.