A graduate of the Australian Film, Television and Radio School, and Head of Screenwriting there since 1999, Lonie began his writing career with the State Theatre of South Australia at the Adelaide Playhouse, working with and writing for Magpie, the company's theatre-in-education arm. He has credits in film and television, including True Believers (1987), The Paper Man (ABC 1990), GP, Police Rescue and A Country Practice, and has edited a number of scripts. In 1983 he translated Frank Wedekind's 1891 play Spring Awakening.