Lathouris has worked on the television series Police Rescue. He appeared in George Miller's film Mad Max (1979) as a car mechanic. He also ran film and drama workshops for the Australian Film Commission.

Lathouris is best known for the role of George Poulos in Heartbreak High, as well as being the series drama coach responsible for developing the skills of the younger actors and actresses who starred in the series. He helped to develop realistic characters from a whole variety of ethnic backgrounds. The series marked a big shift in the way that life in Australia is represented in TV drama. In the past, many shows had not reflected all the different cultures which exist side-by-side in Australia's big cities, and Heartbreak High broke the mould by acknowledging and celebrating the country's cultural mix.

Lathouris is co-screenwriter (alongside George Miller) of Mad Max: Fury Road (2015).