Russell Brand (Arthur)
Helen Mirren (Hobson)
Greta Gerwig (Naomi)
Jennifer Garner (Susan)
Geraldine James (Vivienne)
Luis Guzman (Bitterman)
Nick Nolte (Burt Johnson)
Jose Ramon Rosario (Employment Clerk)
John Hodgman (Candy Store Manager)
Scott Adsit (Gummy Bear Man)
Evander Holyfield (Boxing Trainer)
Peter Van Wagner (Naomi's Dad)
Robert Clohessy (Veteran Cop)
Ed Herbstman (Rookie Cop)
Jared Parker (Wedding Kid)
Tom Toner (Wedding Priest)
Richard Bekins (Chancellor)
Matt Malloy (Spoon Guy)
Nigel Barker (Photographer)
Tuffy Questell (Tito)
Sara Chase (Journalist #1)
Ali Farahnakian (Journalist #2)
Kimberly Pauley (Journalist #3)
Brian McElhaney (College Student)
Charlie Hewson (Receptionist/Best Man)
Peter Brouwer (Auctioneer)
Saul Stein (Officer #2)
Stink Fisher (Foreman)
Debbie Lee Jones (Kissed Woman)
Pascal Yen-Pfister (Maitre D')
Dylan Clark Marshall (Boy on Tour)
Steve Rosen (Grand Central Waiter)
Leslie Hendrix (Alice Johnson)
George Feaster (James)
Ed Jewett (Group Leader)
John Carrafa (Choreographer)
Jennie Eisenhower (Maid of Honor)
Sean G. Tarjoto (Bookstore Clerk)
Pamela Holden Stewart (Librarian)
Skai Jackson (Library Girl #1)
Tori Feinstein (Library Girl #2)
Jackson Nicoll (Library Boy #1)
Caden Draper (Library Boy #2)
Jase Draper (Library Boy #3)
Christina Calph (Tiffany)
Murphy Guyer (Officer Kaplan)