Russell Brand as Arthur

Helen Mirren as Hobson

Greta Gerwig as Naomi Quinn

Jennifer Garner as Susan Johnson

Geraldine James as Vivienne

Luis Guzmán as Bitterman

Nick Nolte as Burt Johnson

Peter Van Wagner as Naomi's Dad

Christina Jacquelyn Calph as Tiffany

John Hodgman as Peter, Candy Store Manager

Murphy Guyer as Officer Kaplan

Saul Stein as Officer #2

José Ramón Rosario as Employment Clerk

John Hodgman as Candy Store Manager

Scott Adsit as Gummy Bear Man

Evander Holyfield as Boxing Trainer

Robert Clohessy as Veteran Cop

Ed Herbstman as Rookie Cop

Jared Parker as Wedding Kid

Tom Toner as Wedding Priest

Richard Bekins as Chancellor

Matt Malloy as Spoon Guy

Nigel Barker as Photographer

Tuffy Questell as Tito

Sara Chase as Journalist #1

Ali Reza as Journalist #2

Brian McElhaney as College Student

Charlie Hewson as Receptionist / Best Man

Peter Brouwer as Auctioneer

Stink Fisher as Foreman

Debbie Lee Jones as Kissed Woman

Pascal Yen-Pfister as Maitre D'

Dylan Clark Marshall as Boy on Tour

Steve Rosen as Grand Central Waiter

Leslie Hendrix as Alice Johnson

George Feaster as James

Ed Jewett as Group Leader

John Carrafa as Choreographer

Jennie Eisenhower as Maid of Honor

Sean Tarjyoto as Bookstore Clerk

Pamela Stewart as Librarian

Skai Jackson as Library Girl #1

Tori Feinstein as Library Girl #2

Jackson Nicoll as Library Boy #1

Devin Almonte as Susan's Bridesmaid (uncredited)

Jamie Choi as Bridesmaid (uncredited)

Tatsumi Romano as Tour Girl (uncredited)

Chelsey Donn as Clerk (uncredited)