Irwin is best known for his roles as Adrian Powell in the Lifetime comedy-drama series Devious Maids and as Graham Chase in the mid-1990s drama My So-Called Life.
He joined the Steppenwolf Theatre Company in 1979, where he performed alongside Laurie Metcalf, John Malkovich, Joan Allen, and Gary Sinise.
[3] He starred as Graham Chase, the soft-spoken father in the 1994 ABC television series My So-Called Life.
In 1999, he starred in No Higher Love, with Katey Sagal and Annabeth Gish, about a woman with a terminal illness who chooses someone to take over for her as wife and mother.
From 2013 to 2016, Irwin starred opposite Rebecca Wisocky in the four seasons that were produced of the Lifetime television comedy-drama series Devious Maids.