[2] After minor one-time roles on the television series Riptide and The Link Men, Maguire made his feature film debut in The Demonstrator with Joe James and Irene Inescort.
That same year, he starred with Tom Oliver and Kate Sheil in David Williamson's A Handful of Friends at the Russell Street Theatre in Melbourne.
A late arrival during the first season of Prisoner, Maguire joined the cast in mid 1979 as Deputy Governor Jim Fletcher and eventually became the only main male character during his three years on the series.
As one of the school's tutors and the father of the disfigured Michelle (Rowena Mohr), his time on the series dealt with Rivers' guilt over his daughter's accident while dealing with his unhappily married wife Yvonne (Suzy Gashler).
[7] After the series' cancellation, Maguire made a guest appearance on Special Squad and had supporting roles in The Surfer and Alice to Nowhere before returning to the stage in 1986 to perform in David Williamson's Sons of Cain which ran for five-months in London's West End.
Maguire also appeared during the final season of the soap opera The Power, The Passion as a police investigator and ex-boyfriend of one of the central characters, Ellen Byrne Edmonds (Olivia Hamnett).
In 1993, he and Lance Peters co-wrote Gross Misconduct, later directed by George T. Miller and, the following year, wrote Seduce Me: Pamela Principle 2 and was the script supervisor for Tunnel Vision.