Zachary Gordon character Greg Heffley
Robert Capron character Rowley Jefferson
Steve Zahn character Frank Heffley
Devon Bostick character Rodrick Heffley
Rachael Harris character Susan Heffley
Chloë Grace Moretz character Angie Steadman
Laine MacNeil character Patty Farrell
Andrew McNee character Coach Malone
Connor Fielding character Manny Heffley
Owen Fielding character Manny Heffley
Karan Brar character Chirag Gupta
Grayson Russell character Fregley
Alex Ferris character Collin
Belita Moreno character Mrs. Norton
Rob LaBelle character Mr. Winsky
Nicholas Carey character Pete Hosey
Samuel Patrick Chu character Carter
Donnie MacNeil character Wade
Samantha Page character Shelley
Ava Hughes character Marley
Owen Best character Bryce Anderson
Cainan Wiebe character Quentin
Cole Heppell character Quentin's Sidekick
Harrison Houde character Darren Walsh
Severin Korfer character Dieter Muller
Jennifer Clement character Mrs. Flint
Karin Konoval character Mrs. Irvine
Raugi Yu character Vice Principal Roy
Kaye Capron character Rowley's Mom
Jake D. Smith character Archie Kelly
Talon Dunbar character Arthur
Naomi Dane character Cheese Girl
Willem Jacobson character Cheese Boy
Sean Bygrave character Coach Brewer
Maxine Miller character Elderly Woman
Taya Clyne character Granddaughter
Nathaniel Marten character Grown-Up Greg
Peter New character Grown-Up Quentin
Nikki Frazer character Lunch Girl #1
Greta Makena Gibson character Lunch Kid #2
Nathan Smith character Kindergarten Boy
Kinua McWatt character Kindergarten Girl
Dylan Bell character Kindergarten Greg
Madison Bell character Kindergarten Patty
Adom Osei character Marty Porter
Alf Humphreys character Mr. Jefferson
Brent Chapman character Mr. Parnell
Rylee Stiles character Preston
Ryan Grantham character Rodney James
Ethan Shankaruk character Snot Kid
Jesse Wheeler character Unpopular 80s Boy
Paul Hubbard character Brock Branigan
Brett Dier character 80s Breakdancer
Brandon Barton character 80s Jock Boy
Cindy Busby character 80s Popular Girl
Alicia Takase Lui character Audition Kid
Jay Sidhu character Audition Kid
Tori Christianson character Audition Kid
Emerald Schreier character Audition Kid
Ben Mitchell character Audition Kid
Haris Cash character Audition Kid
Mariah Crudo character Audition Kid
Alistair Abell character Male Reporter (voice)
Tara McGuire character Female Reporter (voice)
Aidan Gebert character Löded Diper
Cameron Krpan character Löded Diper
Paolo Tolfo character Löded Diper
L.J. Benet character Greg Heffley (singing voice) (uncredited)
Kaitlin Cheung character Kindergarten Child (uncredited)
Amy Esterle character Waitress (uncredited)
Gabrielle Rose character Fregley's Mom (Uncredited)
Billie Eilish character Audience Kid (uncredited)
