 Wesley KimmelGreg Heffley (voice) | Greg Heffley (voice) |
 Erica CerraSusan (voice) | Susan (voice) |
 Christian ConveryFregley (voice) | Fregley (voice) |
 Chris DiamantopoulosFrank (voice) | Frank (voice) |
 Hunter DillonRodrick (voice) | Rodrick (voice) |
| SSpencer HowellRowley Jefferson (voice) | Rowley Jefferson (voice) |
 Gracen NewtonManny (voice) | Manny (voice) |
 Gabriel IglesiasOfficer Vasquez (voice) | Officer Vasquez (voice) |
 Ego NwodimOfficer Leonard (voice) | Officer Leonard (voice) |
 Lisa Ann WalterGabby (voice) | Gabby (voice) |
 Randy PearlsteinMr. Jefferson (voice) | Mr. Jefferson (voice) |
 Anthony ParntherNutcracker (voice) | Nutcracker (voice) |
 Windham RotundaPrison Guard (voice) | Prison Guard (voice) |
| JJeannette ReyesWeatherperson (voice) | Weatherperson (voice) |
| WWill KinneyHooligan #1 (voice) | Hooligan #1 (voice) |
| GGrant KinneyHooligan #2 (voice) | Hooligan #2 (voice) |
 Juliet DonenfeldAdditional Voices (voice) | Additional Voices (voice) |
 Johnny GidcombAdditional Voices (voice) | Additional Voices (voice) |
 Luke LoweAdditional Voices (voice) | Additional Voices (voice) |
 Matt NolanAdditional Voices (voice) | Additional Voices (voice) |
| LLily OliverAdditional Voices (voice) | Additional Voices (voice) |
| CCarson PakAdditional Voices (voice) | Additional Voices (voice) |
 Chrystee PharrisAdditional Voices (voice) | Additional Voices (voice) |
 Somali RoseAdditional Voices (voice) | Additional Voices (voice) |
| MMarley SoleilAdditional Voices (voice) | Additional Voices (voice) |
 Benjamin ValicAdditional Voices (voice) | Additional Voices (voice) |
 Paul-Mikél WilliamsAdditional Voices (voice) | Additional Voices (voice) |
