Acting

2024

2 episodes as Dr. Yablonski

2023

1 episode as Professor James Moriarty

2022

1 episode as Vic Wallace

2020

1 episode as Self

2019		Elementary 1 episode as Antoine LaGrange
2019		The Good Fight 1 episode as Professor Harrison

2017

2 episodes as Baldur Magnusson

2015

1 episode as Jacob Skolimski

2010

1 episode

2008

1 episode as Dr. Morgan Remus

2002

1 episode as Dr. Shafer

2000

2 episodes 1 episode as Judge Barton Wolfe

1999

1 episode as Niles (archive footage)

1997		Remember WENN 1 episode as Desmond Quist
1997		Chicago Hope 2 episodes
1997		Duckman 1 episode

1993

145 episodes as Niles

1992		Murder, She Wrote 1 episode as Neal Dishman
1992		L.A. Law 1 episode as C. Howard Grady
1992		Columbo 1 episode as Alex Varrick

1989

1 episode as Nicholas Helman

1988		Star Trek: The Next Generation 2 episodes as Professor James Moriarty
1988		Frank's Place 1 episode as Arnold David Tuney
1988		The Equalizer 1 episode as Eddie Mason

1987

4 episodes

1986		Tall Tales & Legends 1 episode as Congressman
1986		Matlock 1 episode
1986		George Washington II: The Forging of a Nation 2 episodes as Patrick Henry
1986		Cheers 1 episode as Mr. Reinhardt

1985		The A-Team 1 episode as Phillips
1985		Scarecrow and Mrs. King 2 episodes
1985		Remington Steele 1 episode as Pierre Fumar

1984		Cagney & Lacey 1 episode
1984		Highway to Heaven 1 episode

1980

249 episodes as Eliot Carrington

1974

1 episode as Moulineaux