Greg Heffley

Zachary Gordon

Rowley Jefferson

Robert Capron

Susan Heffley

Rachael Harris

Frank Heffley

Steve Zahn

Rodrick Heffley

Devon Bostick

Angie Steadman

Chloë Grace Moretz

Manny Heffley

Connor Fielding

Manny Heffley

Owen Fielding

Patty Farrell

Laine MacNeil

Coach Malone

Andrew McNee

Chirag Gupta

Karan Brar

Fregley

Grayson Russell

Collin

Alex Ferris

Mrs. Norton

Belita Moreno

Mr. Winsky

Rob LaBelle

Pete Hosey

Nicholas Carey

Carter

Samuel Patrick Chu

Wade

Donnie MacNeil

Shelly

Samantha Page

Marley

Ava Hughes

Bryce Anderson

Owen Best

Quentin

Cainan Wiebe

Quentin's Sidekick

Cole Heppell

Darren Walsh

Harrison Houde

Dieter Muller

Severin Korfer

Mrs. Flint

Jennifer Clement

Mrs. Irvine

Karin Konoval

Vice Principal Roy

Raugi Yu

Rowley's Mom

Kaye Capron

Archie Kelly

Jake D. Smith

Arthur

Talon Dunbar

Cheese Girl

Naomi Dane

Cheese Boy

Willem Jacobson

Coach Brewer

Sean Bygrave

Elderly Woman

Maxine Miller

Granddaughter

Taya Clyne

Grown-Up Greg

Nathaniel Marten

Grown-Up Quentin

Peter New

Lunch Girl #1

Nikki Frazer

Lunch Girl #2

Greta Gibson

Lunch Kid #2

Greta Makena Gibson

Kindergarten Boy

Nathan Smith

Kindergarten Girl

Kinua McWatt

Kindergarten Girl

Kina Mori McWatt

Kindergarten Greg

Dylan Bell

Kindergarten Patty

Madison Bell

Marty Porter

Adom Osei

Mr. Jefferson

Alf Humphreys

Mr. Parnell

Brent Chapman

Preston

Rylee Stiles

Rodney James

Ryan Grantham

Snot Kid

Ethan Shankaruk

Unpopular '80s Boy

Jesse Wheeler

Brock Branigan

Paul Hubbard

'80s Breakdancer

Brett Dier

'80s Jock Boy

Brandon Barton

'80s Popular Girl

Cindy Busby

Audition Kid

Alicia Takase Lui

Audition Kid

Jay Sidhu

Audition Kid

Tori Christianson

Audition Kid

Emerald Schreier

Audition Kid

Benjamin D. Mitchell

Audition Kid

Ben Mitchell

Aduition Kid

Haris Cash

Audition Kid

Mariah Crudo

Löded Diper

Aidan Gebert

Male Reporter (voice)

Alistair Abell

Female Reporter (voice)

Tara McGuire

Löded Diper

Cameron Krpan

Löded Diper

Paolo Tolfo

Mr. Winsky

Rob La Belle

Waitress (uncredited)

Amy Esterle

Parent (uncredited)

John Cygan