John Beckwith

Owen Wilson

Jeremy Klein

Vince Vaughn

Treasury Secretary William Cleary

Christopher Walken

Claire Cleary

Rachel McAdams

Gloria Cleary

Isla Fisher

Kathleen Cleary

Jane Seymour

Zack "Sack" Lodge

Bradley Cooper

Grandma Mary

Ellen Albertini Dow

Todd Cleary

Keir O'Donnell

Father O'Neil

Henry Gibson

Mr. Kroeger

Dwight Yoakam

Randolph

Ron Canada

Trap

David Conrad

Christina

Jennifer Alden

Chaz's Girlfriend

Summer Altice

Mrs. Kroeger

Rebecca De Mornay

Christina Cleary

Jenny Alden

Betty Cleary

Betsy Ames

Craig

Geoff Stults

Jennifer

Camille Anderson

Best Man

Larry Joe Campbell

Vivian

Diora Baird

Attorney

James McDonnell

Italian Wedding Swing Dancer

Jed Bernard

Ivana

Ivana Bozilovic

Attorney

Jesse Henecke

Chazz Reinhold (uncredited)

Will Ferrell

Old Jewish Man

Lou Cutell

Old Jewish Woman

Sparkle

Old Italian Man

Frank Ray Perilli

Old Italian Woman

Patricia Place

Old Chinese Man

Chao Li Chi

Old Irish Woman

Norma Michaels

Old Indian Man

Noel De Souza

Brunette

Rachel Sterling

Frank Meyers

Ned Schmidtke

Woman

Jennifer Massey

Bratty Kid

Dylan James Turner

Flower Girl

Sophia Blouin

Franklin

Stephen J. Downs

Secret Service Agent

Mark Duane Anderson

John McCain (uncredited)

John McCain

Elderly Woman

Irene Roseen

Rabbi

Jules Mandel

Flip

Carson Elrod

Kip

Joshua Wheeler

Ken

John G. Pavelec

Priest

Charles Kahlenberg

Chazz's Mom

Kathryn Joosten

Chazz's Girlfriend

Karen Miller

Woman at Jewish Reception

Tanaya Nicole

Hindu Woman

Naureen Zaim

Girl at Irish Wedding

Cindy Taylor

Girl Who Cries

Melanie Hawkins

Wedding Planner

Lisa Beach

Wedding Planner

Lovelynn Vanderhorst

Woman at Table

Phyllis Samhaber

Man at Table

O.J. Watson

Helicopter Pilot

Al Cerullo

James Carville (uncredited)

James Carville

Woman in Hat (uncredited)

Lindsay Schoneweis

Bridesmaid (uncredited)

Kelsey Wedeen

Funeral Mourner (uncredited)

Brian T. Lynch

Irish Waiter (uncredited)

Joe Koons

Wedding Guest (uncredited)

Brie Garcia