This intimate documentary portrait examines one of the world's most inventive comedians. Told largely through Robin's own voice and using a wealth of never-before-seen archival footage, the film goes through the extraordinary life and career of Robin Williams.
| Name | Type | Role | |
|---|---|---|---|
| Nancy Abraham | Producer | ||
| Alex Gibney | Producer | ||
| Marina Zenovich | Executive Producer | ||
| Sheila Nevins | Executive Producer | ||
| David Steinberg | Executive Producer | ||
| Kristen Vaurio | Executive Producer | ||
| Marina Zenovich | Director | ||
| Matt Damon | Actor | Himself (archival footage) | |
| Shane Fistell | Actor | Himself (archival footage) | |
| John C. Reilly | Actor | Himself (archival footage) | |
| Linda Ronstadt | Actor | Herself (archival footage) | |
| Kate Capshaw | Actor | Herself (archival footage) | |
| Scott Marshall | Actor | Himself | |
| Marsha Garces Williams | Actor | Herself (archival footage) | |
| Julie Kavner | Actor | Herself (archival footage) | |
| Salma Hayek | Actor | Herself (archival footage) | |
| Stu Smiley | Actor | Himself | |
| Michael Douglas | Actor | Himself (archival footage) | |
| Renée Zellweger | Actor | Herself (archival footage) | |
| Dick Cavett | Actor | Himself (archival footage) | |
| Kathy Bates | Actor | Herself (archival footage) | |
| Don Most | Actor | Himself (archival footage) | |
| Roseanne Barr | Actor | Herself (archival footage) | |
| Jack Paar | Actor | Himself (archival footage) | |
| Sally Field | Actor | Herself (archival footage) | |
| Andy Kaufman | Actor | Himself (archival footage) | |
| Michael Vartan | Actor | Himself (archival footage) | |
| Joan Rivers | Actor | Herself (archival footage) | |
| Tony Danza | Actor | Himself (archival footage) | |
| Whoopi Goldberg | Actor | Herself | |
| Lyle Waggoner | Actor | Himself (archival footage) | |
| Drew Carey | Actor | Himself (archival footage) | |
| Elizabeth Kerr | Actor | Herself (archival footage) | |
| Robin Williams | Actor | Himself (archival footage) | |
| George Martin | Actor | Himself (archival footage) | |
| Zak Williams | Actor | Himself | |
| Shelley Duvall | Actor | Herself (archival footage) | |
| John Houseman | Actor | Himself (archival footage) | |
| Steven Spielberg | Actor | Himself (archival footage) | |
| Catherine Zeta-Jones | Actor | Herself (archival footage) | |
| John Chancellor | Actor | Himself (archival footage) | |
| John Belushi | Actor | Himself (archival footage) | |
| Mark Rasmussen | Actor | Himself | |
| Jeff Bridges | Actor | Himself (archival footage) | |
| Tom Poston | Actor | Himself (archival footage) | |
| Ethan Hawke | Actor | Himself (archival footage) | |
| Nicole Kidman | Actor | Herself (archival footage) | |
| Valerie Velardi | Actor | Herself | |
| Bobcat Goldthwait | Actor | Himself | |
| Joe Rogan | Actor | Himself (archival footage) | |
| Pam Dawber | Actor | Herself | |
| Andy Warhol | Actor | Himself (archival footage) | |
| George Carlin | Actor | Himself (archival footage) | |
| Jay Leno | Actor | Himself (archival footage) | |
| Steve Martin | Actor | Himself | |
| Stan Wilson | Actor | Himself | |
| David Steinberg | Actor | Himself | |
| Susan Schneider | Actor | Herself (archival footage) | |
| Ron Howard | Actor | Himself (archival footage) | |
| Cher | Actor | Herself (archival footage) | |
| Richard Pryor | Actor | Himself (archival footage) | |
| Lewis Black | Actor | Himself | |
| Nancy Reagan | Actor | Herself (archival footage) | |
| Jerry Brown | Actor | Himself (archival footage) | |
| Philip Seymour Hoffman | Actor | Himself (archival footage) | |
| David Letterman | Actor | Himself | |
| Raquel Welch | Actor | Herself (archival footage) | |
| Dexter Gordon | Actor | Himself (archival footage) | |
| Mark Romanek | Actor | Himself | |
| Daniel Day-Lewis | Actor | Himself (archival footage) | |
| Jim Carrey | Actor | Himself (archival footage) | |
| Forest Whitaker | Actor | Himself (archival footage) | |
| Laura Linney | Actor | Herself (archival footage) | |
| Steve Allen | Actor | Himself (archival footage) | |
| Ed McMahon | Actor | Himself (archival footage) | |
| Henry Winkler | Actor | Himself (archival footage) | |
| Holly Hunter | Actor | Herself (archival footage) | |
| Howard Storm | Actor | Himself | |
| Garry Shandling | Actor | Himself (archival footage) | |
| Craig Ferguson | Actor | Himself (archival footage) | |
| Jack Nicholson | Actor | Himself (archival footage) | |
| Billy Crystal | Actor | Himself | |
| Carl Reiner | Actor | Himself (archival footage) | |
| Elayne Boosler | Actor | Herself | |
| Christopher Reeve | Actor | Himself (archival footage) | |
| Oliver Sacks | Actor | Himself (archival footage) | |
| Laurie Williams | Actor | Herself (archival footage) | |
| Conrad Janis | Actor | Himself (archival footage) | |
| James Lipton | Actor | Himself (archival footage) | |
| Woody Harrelson | Actor | Himself (archival footage) | |
| Martin Scorsese | Actor | Himself (archival footage) | |
| Robert De Niro | Actor | Himself (archival footage) | |
| Anson Williams | Actor | Himself (archival footage) | |
| Johnny Carson | Actor | Himself (archival footage) | |
| Garry Marshall | Actor | Himself (archival footage) | |
| Robert Altman | Actor | Himself (archival footage) | |
| Edward Norton | Actor | Himself (archival footage) | |
| Jonathan Winters | Actor | Himself (archival footage) | |
| Dave Chappelle | Actor | Himself (archival footage) | |
| Eric Idle | Actor | Himself | |
| Bennett Tramer | Actor | Himself |