Born in Pomona, California, on April 28, 1981, Alba, whose father was in the Air Force, moved with her family to Biloxi, Mississippi, when she was an infant, but she eventually moved back to California nine years later. It was back in California that she embarked on an acting career; having been in love with the idea of acting since she was five, Alba took her first acting class at the age of 12, and nine months later, she landed her first agent.
She got her start on television, making appearances on shows like Beverly Hills 90210, and she made her film debut in the 1994 kids comedy Camp Nowhere. Originally cast in a minor role in the film, she got her first big break when the principal actress dropped out and she was asked to take over.
Following her debut, Alba did a great deal of work on television. She got her first substantial film role as the object of the protagonist's disastrous affection in the teen horror comedy Idle Hands in 1999; that same year, she played one of the nasty popular girls who terrorize Drew Barrymore in the romantic comedy Never Been Kissed.
The following year Alba made waves on the small screen when she was cast in the much hyped Fox series Dark Angel. Executive produced by James Cameron, the rising starlet was cast as a genetically-engeneered woman who escapes from the lab and joins a cyberjournalist named Logan Cale (Michael Weatherly) in his neverending fight against a crime in a post-apocalyptic future. Though the series was cancelled after two seasons, Alba continued to appear in such features as Paranoid (2000) and The Sleeping Dictionary (2003).