Grimes was born in Burlington, Vermont. He made his acting debut in the Buffy, the Vampire Slayer episode Fear Itself in 1999. He is probably best remembered for his recurring role as Nordlund on the television series The O.C. (2003), where he performed alongside Melinda Clarke, Daphne Ashbrook, Ruth Williamson, Barry Wiggins, and stunt performers Shawn Crowder and Joey Anaya. Grimes studied acting under Julie Ariola and John Sarno and stage combat training under Paul Ugalde. Also a trained stage actor, Grimes portrayed leading roles such as Mercutio in Romeo and Juliet, Laertes in Hamlet, and D'Artagnan in The Three Musketeers.