Isaac Skidmore as Greg Heffley

Eli Hayden as Rodrick Heffley

John Orr as Rowley Jefferson

Abe Yates as Fregley

MacGregor Lakes as Jeff Kinney

Pamela Cveticanin as Susan Heffley

Luke Seals as Police Officer

Alex Wright as Extra

Joel Cortez as Extra

Reece Cveticanin as Extra

Sayer Kobersmith as Extra

Autumn Winkler as Extra

Carlton Sears as Extra

James Wright as Extra

Robert Capron as Self (archive footage)

Zachary Gordon as Self (archive footage)

Jeff Kinney as Self (archive footage)