Michael Stuhlbarg

Larry Gopnik

Richard Kind

Uncle Arthur

Fred Melamed

Sy Ableman

Sari Lennick

Judith Gopnik

Aaron Wolff

Danny Gopnik

Peter Breitmayer

Mr. Brandt

Ari Hoptman

Arlen Finkle

Alan Mandell

Rabbi Marshak

Amy Landecker

Mrs. Samsky

George Wyner

Rabbi Nachtner

Michael Tezla

Dr. Sussman

Katherine Borowitz

Friend at the Picnic

Steve Park

Clive's Father

Allen Lewis Rickman

Shtetl Husband

Yelena Shmulenson

Shtetl Wife

Fyvush Finkel

Dybbuk?

Raye Birk

Dr. Shapiro

Jane Hammill

Larry's Secretary

Simon Helberg

Rabbi Scott

Adam Arkin

Divorce Lawyer

James Cada

Cop #1

Michael Lerner

Solomon Schlutz

Charles Brin

Hebrew School Principal

Tyson Bidner

Magbiah

Warren Keith

Dick Dutton (voice)

Tim Russell

Detective #1

Scott Thompson Baker

Sci-Fi Movie Hero

Punnavith Koy

Physics Nerd (uncredited)

Amanda Day

Physics Student (uncredited)