Michael Stuhlbarg

Larry Gopnik

Richard Kind

Uncle Arthur

Fred Melamed

Sy Ableman

Sari Lennick

Judith Gopnik

Aaron Wolff

Danny Gopnik

Jessica McManus

Sarah Gopnik

Peter Breitmayer

Mr. Brandt

Alan Mandell

Rabbi Marshak

Amy Landecker

Mrs. Samsky

George Wyner

Rabbi Nachtner

Katherine Borowitz

Friend at the Picnic

Steve Park

Clive's Father

Allen Lewis Rickman

Shtetl Husband

Fyvush Finkel

Dybbuk?

Raye Birk

Dr. Shapiro

Claudia Wilkens

Marshak's Secretary

Simon Helberg

Rabbi Scott

Adam Arkin

Divorce Lawyer

Michael Lerner

Solomon Schlutz

Charles Brin

Hebrew School Principal

Tyson Bidner

Magbiah

Warren Keith

Dick Dutton (voice)

Scott Thompson Baker

Sci-Fi Movie Hero

Punnavith Koy

Physics Nerd (uncredited)

Joel Thingvall

Bar Mitzvah Guest (uncredited)

Amanda Day

Physics Student (uncredited)