Michael Stuhlbarg as Larry Gopnik

Richard Kind as Uncle Arthur

Fred Melamed as Sy Ableman

Sari Lennick as Judith Gopnik

Aaron Wolff as Danny Gopnik

Jessica McManus as Sarah Gopnik

Peter Breitmayer as Mr. Brandt

Brent Braunschweig as Mitch Brandt

David Kang as Clive Park

Benjamin Portnoe as Danny's Reefer Buddy

Jack Swiler as Boy on Bus

Andrew S. Lentz as Cursing Boy on Bus

Jon Kaminski Jr. as Mike Fagle

Ari Hoptman as Arlen Finkle

Alan Mandell as Rabbi Marshak

Amy Landecker as Mrs. Samsky

George Wyner as Rabbi Nachtner

Michael Tezla as Dr. Sussman

Katherine Borowitz as Friend at the Picnic

Steve Park as Clive's Father

Allen Lewis Rickman as Shtetl Husband

Yelena Shmulenson as Shtetl Wife

Fyvush Finkel as Dybbuk?

Ronald Schultz as Hebrew School Teacher

Raye Birk as Dr. Shapiro

Jane Hammill as Larry's Secretary

Claudia Wilkens as Marshak's Secretary

Simon Helberg as Rabbi Scott

Adam Arkin as Divorce Lawyer

James Cada as Cop #1

Michael Lerner as Solomon Schlutz

Charles Brin as Hebrew School Principal

Michael Engel as Torah Blesser

Tyson Bidner as Magbiah

Phyllis Harris as Hebrew School Tea Lady

Piper Sigel-Bruse as D'vorah

Hannah Nemer as Sarah's Friend

Rita Vassallo as Law Firm Secretary

Warren Keith as Dick Dutton (voice)

Neil Newman as Cantor

Tim Russell as Detective #1

Jim Lichtscheidl as Detective #2

Wayne A. Evenson as Russell Krauss

Scott Thompson Baker as Sci-Fi Movie Hero

Landyn Banx as Physics Student (uncredited)

Punnavith Koy as Physics Nerd (uncredited)

Joel Thingvall as Bar Mitzvah Guest (uncredited)

Amanda Day as Physics Student (uncredited)