 | Jason Segel als Peter Bretter |
 | Kristen Bell als Sarah Marshall |
 | Mila Kunis als Rachel Jansen |
 | Russell Brand als Aldous Snow |
 | Bill Hader als Brian Bretter |
 | Jonah Hill als Matthew Van Der Wyk |
 | Liz Cackowski als Liz Bretter |
 | Jack McBrayer als Darald |
 | Maria Christina Thayer als Wyoma |
 | Paul Rudd als Chuck |
 | Jason Bateman als Animal Instincts Detective |
 | William Baldwin als Detective Hunter Rush |
 | Kristen Wiig als Yoga Instructor |
 | Da'Vone McDonald als Dwayne |
 | Steve Landesberg als Dr. Rosenbaum |
 | Kalani Robb als Helpful Hawaiian Waiter |
 | Murray Miller als Photographer |
 | Taylor Wily als Kemo |
 | Kala Alexander als Greg |
 | Francesca Delbanco als Hostess at Buffet |
 | Branscombe Richmond als Keoki |
 | Billy Bush als Billy Bush (Himself) |
 | Peter Gray Lewis als Suspect on Animal Instincts |
 | Trula M. Marcus als Lawyer on Crime Scene |
 | Kirk Fox als Mixer |
 | June Diane Raphael als Ann |
 | Ahna O'Reilly als Leslie |
 | Tanisha Harper als Model |
 | Carla Gallo als Gag Me Girl |
 | Cynthia Lamontagne als Female Bartender |
 | Max Alexander als Big Dracula Head |
| Carla Alapont als Spanish Sex Girl |
 | Michael Oosterom als Puppeteer |
| Peter Salett als Keyboard Player |
 | Jesse Heiman als Theater Audience Member (uncredited) |
| Judd Apatow | Producer |
| Richard Vane | Executive Producer |
| William Kerr | Editor |
| Rodney Rothman | Executive Producer |
| Lyle Workman | Music |
| Nicholas Stoller | Director |
| Jason Segel | Screenplay |
| Shauna Robertson | Producer |
| Russ T. Alsobrook | Director of Photography |
| D. Scott Easton | Unit Production Manager |
| Scott Meehan | Art Direction |
| Alicia Maccarone | Set Designer |
| Jerome Fauci | "B" Camera Operator |
| Brent Rice | Leadman |
| Jerome Fauci | Steadicam Operator |
| Michael Trisler | Stunts |
| Bill Matthews | Art Direction |
| Casey Hotchkiss | Camera Operator |
| Chuck 'Chaz' Hosack | Stunts |
| Natalie Bridgman | Stunts |
| Jackson De Govia | Production Design |
| Dawn Massaro | Second Assistant Director |
| Jonathan Karp | Music Supervisor |
| K.C. Fox | Set Decoration |
| Brian L. Keaulana | Stunts |
| Phil Dagort | Set Designer |
| Nadia Paine | Production Supervisor |
| Don Zepfel | Unit Production Manager |
| Leesa Evans | Costume Design |
| Danny Wynands | Stunts |
| Jeanne McCarthy | Casting |
| Gary Marcus | First Assistant Director |
| Tim Trella | Stunt Coordinator |
| Tim Trella | Second Unit Director |
| Dan Squires | Second Assistant "B" Camera |
| Jason Garcia | First Assistant "A" Camera |
| Jeff Graham | First Assistant "B" Camera |
| Rigney Sackley | Second Assistant "A" Camera |
| Richard Van Dyke | Production Sound Mixer |
| Chet Leonard | Cableman |
| Eugene McCarthy | Property Master |
| Brenda Lopez | Script Supervisor |
| Sarah Sprague | Production Coordinator |
| Doug DuRose | Assistant Property Master |
| Desne J. Holland | Makeup Artist |
| Kraig Kishi | Boom Operator |
| Tracey Levy | Key Makeup Artist |
| Curtis Bradford | Gaffer |
| Vickie Mynes | Hairstylist |
| Hayley Stuppel | Set Costumer |
| Linda Arnold | Key Hair Stylist |
| Molly Grundman-Gerbosi | Key Costumer |
| Grace Lambert Pyke | Key Costumer |
| Peggy Casey | Set Buyer |
| Michelle Margolis | Set Costumer |
| Suzanne Cranfill | Costume Supervisor |
| Cynthia C. Rebman | Set Dresser |
| Ariel Gold | Set Costumer |
| Jesse Heiman | Stand In |
| Timothy Hedgecock | Best Boy Electric |
| Samantha Bahramian | Electrician |
| Hector Corona | Electrician |
| Daniel L. Magat | Electrician |
| Robert Murphy | Electrician |
| Jason Young | Electrician |
| T. Daniel Scaringi | Key Grip |
| Robert Chinello | Best Boy Grip |
| Michael Wahl | Dolly Grip |
| Jennifer Möller | Art Department Coordinator |
| Jon G. Belyeu | Special Effects Coordinator |
| George H. Anderson | Supervising Sound Editor |
| Orest Sushko | Sound Re-Recording Mixer |
| Adam Jenkins | Sound Re-Recording Mixer |
| Dov Samuel | First Assistant Editor |
| Brian Scott Olds | Assistant Editor |
| Tammy Fearing | ADR Supervisor |
| James Matheny | Dialogue Editor |
| Larry Kemp | Dialogue Editor |
| Cindy Marty | Sound Effects Editor |
| Joe Schiff | Foley Editor |
| Roy Seeger | Foley Editor |
| Cherie Tamai | First Assistant Sound Editor |
| Jan Dennehy | Production Accountant |
| Carole Humphreys | Assistant Accountant |
| Angela Randazzo | Payroll Accountant |
| Missy Eustermann | Post Production Accountant |
| Nicole Abellara Hallman | Casting Associate |
| Leslie Woo | Casting Assistant |
| Rich King | Extras Casting |
| Chamonix Bosch | Second Second Assistant Director |
| John H. Samson | Construction Coordinator |
| Damon Hight | Construction Foreman |
| William Ballard | Transportation Coordinator |
| Tom Rebber | Transportation Captain |
| Glen Wilson | Still Photographer |
| Claire Raskind | Unit Publicist |
| Wendy Hoffmann | ADR Voice Casting |
| Greg Steele | ADR Mixer |
| Greg Zimmerman | ADR Recordist |
| Andy Malcolm | Foley Artist |
| Goro Koyama | Foley Artist |
| Jonathan Karp | Music Editor |
| Lyle Workman | Orchestrator |
| Jimmy Fusil | Digital Intermediate Producer |
| Gary Burritt | Negative Cutter |
| Thom 'Coach' Ehle | Dolby Consultant |
