Baker began acting on Australian television during the late 1980s using the name "Simon Denny". He first appeared in music videos for Melissa Tkautz ("Read My Lips") and Australian dance outfit Euphoria ("Love You Right") in 1991 before appearing in the successful series E Street, Home and Away and Heartbreak High. As "Simon Baker Denny" he was a co-star of the David Croft/Jeremy Lloyd sitcom pilot, Which Way to the War, which was not developed into a series.
In 1995, he was in an episode of the Australian television (ABC TV) series Naked (episode title: Blindside Breakaway) in the role of a rugby player. His character was an easy going mummy's boy until he met a girl who challenged his safe existence. He called the role "physically demanding" due to the fact most of the extras were actual rugby players. At the time he referred to this role as an important opportunity as well as being "the best job I've had in my life". He went on to say it was going to be hard afterwards to want to do anything offered.
He relocated to the United States, where he was cast in a small role in L.A. Confidential, which led to further opportunities in supporting roles in films. In 1998 he starred in a small, independent film by filmmaker Stephen Grynberg titled "Love from Ground Zero", and in 1999 appeared in Ang Lee's Ride with the Devil. In 2000, he played Michael Scott in Adam Collis's Sunset Strip. He also played an astronaut in Red Planet with Val Kilmer, Carrie-Anne Moss and Benjamin Bratt. He played the male lead in the television series The Guardian for three seasons beginning in 2001, and also appeared in The Affair of the Necklace. He played a distressed husband in 2004's Book of Love. In 2005, he starred as an altruistic hero in George A. Romero's Land of the Dead.More?