who plays agent callen on ncis los angeles
G. Callen G. Callen (born: Grisha Alekandrovich Nikolaev) is a fictional character in the show NCIS: Los Angeles portrayed by Chris O'Donnell. He is an NCIS Special Agent in Charge, and the senior agent assigned to the Office of Special Projects. O'Donnell made his first appearance during NCIS' sixth season episode "Legend (Part 1)".
Renée Felice Smith RenÃ©e Felice Smith (born January 16, 1985)[1] is an American actress. She is known for portraying Nell Jones on NCIS: Los Angeles, since joining the series that began in 2010.