 | Billy Crystal | Mike Wazowski (voice) |
 | John Goodman | James 'Sulley' Sullivan (voice) |
 | Helen Mirren | Dean Hardscrabble (voice) |
 | Steve Buscemi | Randall Boggs (voice) |
 | Peter Sohn | Scott 'Squishy' Squibbles (voice) |
 | Joel Murray | Don Carlton (voice) |
 | Aubrey Plaza | Claire Wheeler (voice) |
 | Sean Hayes | Terri Perry (voice) |
 | Dave Foley | Terry Perry (voice) |
 | Charlie Day | Art (voice) |
 | Alfred Molina | Professor Knight (voice) |
 | Tyler Labine | Brock Pearson (voice) |
 | Nathan Fillion | Johnny Worthington (voice) |
 | Bobby Moynihan | Chet Alexander (voice) |
| Noah Johnston | Young Mike (voice) |
 | Julia Sweeney | Ms. Squibbles (voice) |
 | Bonnie Hunt | Karen Graves (voice) |
 | John Krasinski | Frank McCay (voice) |
 | Bill Hader | Referee (voice) |
 | Beth Behrs | Carrie Williams (voice) |
 | Bob Peterson | Roz (voice) |
 | John Ratzenberger | Yeti (voice) |
 | Lori Alan | Additional Voices (voice) |
 | Carlos Alazraqui | Additional Voices (voice) |
 | Jack Angel | Additional Voices (voice) |
 | Bob Bergen | Additional Voices (voice) |
 | Gregg Berger | Additional Voices (voice) |
 | Rodger Bumpass | Additional Voices (voice) |
 | Neil Campbell | Additional Voices (voice) |
 | Frank Oz | Fungus (voice) |
 | Ava Acres | Additional Children's Voices (voice) |
 | Sherry Lynn | Additional Voices (voice) |
 | Paul Lazenby | Monster (voice, uncredited) |
 | Aramé Scott | Additional Children's Voices (voice) |
| Joseph John Schirle | Additional Children's Voices (voice) |
 | Kristen Li | Additional Children's Voices (voice) |
 | Davin Ransom | Additional Children's Voices (voice) |
 | Raymond Ochoa | Additional Children's Voices (voice) |
| Calum John | Additional Children's Voices (voice) |
 | Montse Hernandez | Additional Children's Voices (voice) |
| Mason Cook | Additional Children's Voices (voice) |
| Makenna Cowgill | Additional Children's Voices (voice) |
 | Tyree Brown | Additional Children's Voices (voice) |
| Jack Bright | Additional Children's Voices (voice) |
 | Isabella Acres | Additional Children's Voices (voice) |
 | April Winchell | Additional Voices (voice) |
| Colette Whitaker | Additional Voices (voice) |
 | Jim Ward | Additional Voices (voice) |
 | Marcia Wallace | Additional Voices (voice) |
 | David Theune | Additional Voices (voice) |
 | Tara Strong | Additional Voices (voice) |
 | Mindy Sterling | Additional Voices (voice) |
 | Joel Spence | Additional Voices (voice) |
 | Betsy Sodaro | Additional Voices (voice) |
 | Patrick Seitz | Additional Voices (voice) |
 | Dan Scanlon | Additional Voices (voice) |
 | Jan Rabson | Additional Voices (voice) |
 | Cristina Pucelli | Additional Voices (voice) |
 | Jeff Pidgeon | Additional Voices (voice) |
 | Dannah Feinglass Phirman | Additional Voices (voice) |
 | Donovan Patton | Additional Voices (voice) |
 | Bret 'Brook' Parker | Additional Voices (voice) |
 | Colleen O'Shaughnessey | Additional Voices (voice) |
 | Laraine Newman | Additional Voices (voice) |
 | David Neher | Additional Voices (voice) |
 | Pam Murphy | Additional Voices (voice) |
 | Matthew Mercer | Additional Voices (voice) |
 | Alec Medlock | Additional Voices (voice) |
| Allan McLeod | Additional Voices (voice) |
 | Mickie McGowan | Additional Voices (voice) |
 | Tricia McAlpin | Additional Voices (voice) |
 | Mona Marshall | Additional Voices (voice) |
 | Jason Marsden | Additional Voices (voice) |
 | Danny Mann | Additional Voices (voice) |
 | Dawnn Lewis | Additional Voices (voice) |
 | Elissa Knight | Additional Voices (voice) |
 | John Kassir | Additional Voices (voice) |
 | Brandon Johnson | Additional Voices (voice) |
 | Jess Harnell | Additional Voices (voice) |
| Mike Hanford | Additional Voices (voice) |
 | Daniel Gerson | Additional Voices (voice) |
 | Teresa Ganzel | Additional Voices (voice) |
 | Donald Fullilove | Additional Voices (voice) |
 | Andy Fischer-Price | Additional Voices (voice) |
 | Keith Ferguson | Additional Voices (voice) |
 | Bill Farmer | Additional Voices (voice) |
 | Paul Eiding | Additional Voices (voice) |
| Greg Dykstra | Additional Voices (voice) |
 | John Cygan | Additional Voices (voice) |
 | Sean Conroy | Additional Voices (voice) |
 | Patrick Carlyle | Additional Voices (voice) |
| Natalie Jane Dang | Additional Children's Voices (voice) |
| Gage Davenport | Additional Children's Voices (voice) |
| Ethan Louis Samuels DiSalvio | Additional Children's Voices (voice) |
| Faith Goblirsch | Additional Children's Voices (voice) |
| Brooke Klinger | Additional Children's Voices (voice) |
| Nikolas Michailidis | Additional Children's Voices (voice) |
| Marley Pearson | Additional Children's Voices (voice) |
| Davin Doak | Additional Children's Voices (voice) |
80% 
81%