Brian Dietzen is an American actor whose career started in the early 2000s. He debuted on the sitcom My Guide to Becoming a Rock Star, as well as guest-starred on Boston Public. He next appeared in the musical film From Justin to Kelly. In 2004, he started playing the role of Dr. Jimmy Palmer on NCIS, a character he still plays up to present. While on the show, he had performed in the films Purgatory House, Self-Inflicted, Nowhere to Run, and Every Second Counts. In 2013, he guest-starred in an episode of the TNT series Perception as Mark Leighton.