He studied acting at the National Institute of Dramatic Art (NIDA), where he graduated[3] in 1978.
[4] Grubb played the role of Dr. Geoffrey Standish in the popular series The Flying Doctors.
[3] In 1998, he played The Wolf and Cinderella’s Prince in the Melbourne Theatre Company's production of Stephen Sondheim’s Into the Woods.
[6] In 2016, he played Dimitri Weissman in Sondheim’s Follies at Melbourne Recital Centre.
As of 2020[update] Grubb was reprising his previous role of Detective Bill Graves on Neighbours.