Mark Harmon and Emily Wickersham in NCIS (2003)

Mark Harmon, Wilmer Valderrama, and Cote de Pablo in NCIS (2003)

Mark Harmon, Wilmer Valderrama, Sean Murray, and Emily Wickersham in NCIS (2003)

Mark Harmon and Diona Reasonover in NCIS (2003)

Mark Harmon and Pamela Sue Martin in The Hardy Boys/Nancy Drew Mysteries (1977)

Mark Harmon in The Hardy Boys/Nancy Drew Mysteries (1977)

Mark Harmon and Terry Kiser in The Hardy Boys/Nancy Drew Mysteries (1977)

Mark Harmon, Wilmer Valderrama, David McCallum, Brian Dietzen, and Emily Wickersham in NCIS (2003)

Mark Harmon, Wilmer Valderrama, Emily Wickersham, and Diona Reasonover in NCIS (2003)

Mark Harmon and Maria Bello in NCIS (2003)

Michael Caine, Sally Field, Mark Harmon, Karl Malden, Slim Pickens, Peter Boyle, Shirley Knight, Angela Cartwright, Shirley Jones, and Jack Warden in Beyond the Poseidon Adventure (1979)

Sally Field, Mark Harmon, Karl Malden, Slim Pickens, Angela Cartwright, and Shirley Jones in Beyond the Poseidon Adventure (1979)

Mark Harmon and Sean Murray in NCIS (2003)

Dabney Coleman and Mark Harmon in NCIS (2003)

Mark Harmon, Rocky Carroll, and Chris Nelson Norris in NCIS (2003)

Mark Harmon and Dennis Kort in 240-Robert (1979)

Joanna Cassidy, Mark Harmon, and John Bennett Perry in 240-Robert (1979)

Mark Harmon and Marlee Matlin in Reasonable Doubts (1991)

Mark Harmon, Nike Doukas, and Diona Reasonover in NCIS (2003)

Mark Harmon, Pauley Perrette, Sasha Alexander, David McCallum, and Michael Weatherly in NCIS (2003)

Mark Harmon, Pauley Perrette, Sasha Alexander, David McCallum, Sean Murray, and Michael Weatherly in NCIS (2003)

Mark Harmon and Pauley Perrette in NCIS (2003)

Lauren Holly, Mark Harmon, Pauley Perrette, David McCallum, Michael Weatherly, and Cote de Pablo in NCIS (2003)

Lauren Holly, Mark Harmon, David McCallum, Sean Murray, Michael Weatherly, and Cote de Pablo in NCIS (2003)

Kirstie Alley, Mark Harmon, and Courtney Thorne-Smith in Summer School (1987)

Lauren Holly, Mark Harmon, Pauley Perrette, David McCallum, Sean Murray, Michael Weatherly, and Cote de Pablo in NCIS (2003)