West was born in Baton Rouge, Louisiana to Don Snaith (a drugstore owner who was born in Jamaica) and Catherine, both of whom were musicians; he has a younger sister, Simone, and a much younger half-sister, Marli Ann. His parents divorced and at the age of 10, West moved to California with his mother.
He developed an interest in acting after being forced to take a Drama class in high school, needing that credit to graduate.
His first major role was in 1999's television series, Once and Again, playing "Eli Sammler". West's film debut was a supporting role in the 1999 film Liberty Heights, director Barry Levinson's film about a Jewish family in Baltimore. He also co-starred in the teen comedies "Whatever It Takes" (2000) and Get Over It (2001).
West was subsequently cast opposite singer/actress Mandy Moore in 2002's A Walk to Remember, which was a box office success, grossing $41 million in the United States . In 2003, West appeared in The League of Extraordinary Gentlemen and in 2004, he joined the cast of NBC's long running medical television series, ER. He recently starred in the independent film, What We Do is Secret, playing Darby Crash, a member of the 1970s punk band, The Germs. The film has not yet been released.
West enjoys writing music and playing the guitar. One of his songs, "So What Does It All Mean?", was featured in the soundtrack of his film, A Walk to Remember. He performs in and around Los Angeles, California with his rock band, "Jonny Was" and with the recently reunited band, the Germs, filling in for Darby Crash.
West has dated actresses Rachael Leigh Cook, Marla Sokoloff and Dina Meyer.