Lou Diamond Phillips made his debut in the 1984 science fiction comedy-horror film ‘Interface.’ He played a small role in the film. He got his breakthrough role as ‘Ritchie Valens’ in the biographical drama film 'La Bamba' (1987). The film received a thumbs up from critics and went on to become a commercial success. The following year, he starred as ‘Angel David Guzman’ in the Ramón Menéndez-directed drama film 'Stand and Deliver.' Lou earned 'Independent Spirit Award' as well as a 'Golden Globe' nomination for his performance in the film.
Phillips continued to appear in a host of successful films in the following years, including 'Young Guns' (1988), 'Young Guns II' (1990), 'Courage Under Fire' (1996), and 'The Big Hit' (1998). The year 2001 saw the release of the action-horror film ‘Route 666’ where he played the lead role of ‘Deputy U.S. Marshal Jack La Roca.’
Phillips went on to star in feature films like 'Che' (2008) and 'The 33' (2015), and TV movies like ‘Murder at the Presidio’ (2005) and ‘The Night Stalker’ (2016). He had recurring roles in many TV shows including 'Wolf Lake' (2001-02), ‘Numb3rs’ (2005-2010), and 'Stargate Universe' (2009-11). In 2019, he starred as ‘Johnny Kane’ in the Netflix film ‘The Big Kill.’ Phillips was last seen in the anime-influenced streaming television series ‘Trese’ (2021) where he voiced the character ‘Mayor Sancho Santamaria.’
He made his Broadway debut in 1996 with the musical 'The King and I', in which his portrayal of King Mongkut of Siam received a nomination for a 'Tony Award'. In 2007, he played King Arthur for the touring troupe of Lerner and Loewe's 'Camelot'.
Phillips is all set to appear in the upcoming comedy film ‘Easter Sunday’ directed by Jay Chandrasekhar. He will also be seen in ‘Guns 3: Alias Billy the Kid,’ the third installment of the 'Young Guns' film franchise.