[2] He has headed the kitchen in some of Melbourne's most prominent restaurants including Browns, Burnham Beeches Country House and Hotel Sofitel before opening the award-winning Fenix in 2000 and later selling it to the Leonda by the Yarra group in 2013.

[4] Mehigan was one of the original judges on Network 10's MasterChef Australia with George Calombaris and Matt Preston.

In July 2015, Mehigan began a new TV series called Far Flung with Gary Mehigan, where he travelled to various countries in Asia such as India, Vietnam, Laos, China and South Korea to learn local cooking techniques and recipes, which he uses as inspiration for a recipe he demonstrates at the end of each episode.

After leaving MasterChef Australia, on 23 October 2019 it was announced that Mehigan and fellow MasterChef Australia judge Matt Preston would join Manu Feildel in 2020 with a new show on the Seven Network called Plate of Origin.

[6] In 2022 Mehigan appeared as a guest judge on the twelfth season of My Kitchen Rules.