Steven Mackintosh was born on April 30, 1967, in Cambridge, England. His acting career began in the early '80s with various TV appearances. In 1990, he appeared in the war film Memphis Belle, and two years later, he had a small role in The Muppet Christmas Carol. Mackintosh appeared in Guy Ritchie's feature debut, Lock, Stock and Two Smoking Barrels (1998), and in 2005 he starred in John Maybury's The Jacket.
In 2017, Mackintosh had a starring role in the TV series The Halcyon, and a year later, he appeared in the Netflix series Wanderlust opposite Toni Collette. He married actress Lisa Jacobs in 1989, and they have two children.