| Thomas Middleditch | Richard Hendricks |
| T.J. Miller | Erlich Bachman |
| Josh Brener | Nelson 'Big Head' Bighetti |
| Martin Starr | Bertram Gilfoyle |
| Kumail Nanjiani | Dinesh Chugtai |
| Amanda Crew | Monica Hall
(credit only) |
| Zach Woods | Donald 'Jared' Dunn |
| Matt Ross | Gavin Belson |
| Suzanne Cryer | Laurie Bream
(credit only) |
| Jimmy O. Yang | Jian Yang
(credit only) |
| Bridey Elliott | Winnie |
| Ken Lerner | Arthur |
| Michael McMillian | Aaron 'Double A' Anderson |
| Annie Sertich | C.J. Cantwell |
| Chris Williams | Hoover |
| Cate Cohen | Melinda |
| Julie Dove | Party Stage Manager |
| Alan Gray | Orville (Old Hippy Man) |
| J. Mandyam | Sanjay
(as Jay Mandyam) |
| Miljan Milosevic | Gleb |
| Bridgett Newton | Sasha |
| Sigrid Owen | Elisabet |
| Diallo Riddle | Paul |
| Hanover Savas | Carol |
| Francine Alex | Hawaiian Hula Dancer
(uncredited) |
| Jacquie Cardinale | Pierce
(uncredited) |
| Rachel Daigh | Professional Athlete
(uncredited) |