Zachary Gordon

Greg Heffley

Robert Capron

Rowley Jefferson

Steve Zahn

Frank J. Heffley

Devon Bostick

Rodrick Heffley

Rachael Harris

Susan Heffley

Chloë Grace Moretz

Angie Steadman

Laine MacNeil

Patty Farrell

Andrew McNee

Coach Malone

Connor Fielding

Manny Heffley

Owen Fielding

Manny Heffley

Karan Brar

Chirag Gupta

Grayson Russell

Fregley

Alex Ferris

Collin

Rob LaBelle

Mr. Winsky

Nicholas Carey

Pete Hosey

Samuel Patrick Chu

Carter

Donnie MacNeil

Wade

Samantha Page

Shelley

Ava Hughes

Marley

Owen Best

Bryce Anderson

Cainan Wiebe

Quentin

Harrison Houde

Darren Walsh

Karin Konoval

Mrs. Irvine

Raugi Yu

Vice Principal Roy

Maxine Miller

Elderly Woman

Peter New

Grown-Up Quentin

Greta Makena Gibson

Lunch Kid #2

Alf Humphreys

Mr. Jefferson

Brent Chapman

Mr. Parnell

Ryan Grantham

Rodney James

Ethan Shankaruk

Snot Kid

Paul Hubbard

Brock Branigan

Brett Dier

80s Breakdancer

Cindy Busby

80s Popular Girl

Alistair Abell

Male Reporter (voice)

Amy Esterle

Waitress (uncredited)

John Cygan

Parent (uncredited)