He graduated from Ardsley High School in 1964 and later from the University at Buffalo.
On television, he had a recurring role as crooked New Jersey State Assemblyman Ronald Zellman in seasons three and four of the HBO series The Sopranos (2001-2002) and appeared as George Moore in the first season of the FX series Damages (2007)
He worked at a number of jobs, including teaching, waiting tables, and social worker before settling on acting as a career. Stage
He made his Broadway debut in the musical Dance with Me. Other Broadway credits include The Old Neighborhood, An American Daughter, The Nerd, and Censored Scenes From King Kong.
Off-Broadway he has appeared in Road to Nirvana, The Birthday Party, Isn't It Romantic, Sexual Perversity in Chicago, and A Rosen by Any Other Name. Film
Riegert made his television debut as Cpl. Igor Straminsky in two episodes of M*A*S*H. He has also portrayed New Jersey State Assemblyman Ronald Zellman in The Sopranos and defense attorney Chauncey Zeirko in multiple episodes of Law & Order: Special Victims Unit.
Riegert guest starred in a Season 2 episode of Leverage as corrupt lawyer Peter Blanchard. In 2011, Riegert began a multi-episode arc on One Tree Hill as August Kellerman, Nathan's unforgiving college professor. Riegert appeared as the character George Moore in Season 1 of Damages.
He also appears in a recurring role of Judge Harvey Winter in CBS's The Good Wife. He is currently appearing in Dads as David Sachs, the father of Eli Sachs, played by Seth Green. Director and writer
Riegert made his screenwriting and directorial debuts with By Courier, based on a short story by O. Henry.
Riegert directed and co-wrote King of the Corner, a 2004 film featured at the Newport Film Festival. It stars Peter Riegert and Isabella Rossellini, and includes Eric Bogosian, Dominic Chianese, Beverly D'Angelo and Rita Moreno. Voice work
Riegert narrated the audiobook of Michael Chabon's The Yiddish Policemen's Union, which was nominated for a 2008 Audie Award in literary fiction.
He narrated the audiobook of The Voyage of the Narwhal, a mid-19th century romance with the Arctic, and also read the stories of Raymond Carver. He was also the narrator for The First Basket, a documentary film on professional basketball's influence on Jewish culture.