| Name | Character | Episodes |
|---|---|---|
| Carla Gugino | Dr. Molly Anne Caffrey | 13 |
| Peter Dinklage | Arthur Ramsey | 13 |
| Lauren Tom | Janet TAM | 13 |
| Brent Spiner | Dr. Nigel Fenway | 13 |
| Charles S. Dutton | J.T. Baylock | 13 |
| Brian Van Holt | Sean Cavennaugh | 13 |
| Rob Benedict | Lucas Pegg | 13 |
| Diane Venora | 4 | |
| Kevin Durand | 3 | |
| Jake Abel | 3 | |
| Seamus Dever | Agent Detoro | 2 |
| William Mapother | 2 | |
| Michael Papajohn | 2 | |
| Amanda Fuller | 2 | |
| Jacqueline Kim | 2 | |
| Cameron Monaghan | 1 | |
| Viola Davis | 1 | |
| Kevin Alejandro | 1 | |
| Catherine Bell | 1 | |
| Raphael Sbarge | 1 | |
| Elizabeth Berkley | 1 | |
| Steven R. McQueen | 1 | |
| James Frain | 1 | |
| Lauren Tom | 1 | |
| Wayne Duvall | 1 | |
| Jon Polito | 1 | |
| Joe Penny | 1 | |
| Kevin Kilner | 1 | |
| Cliff DeYoung | 1 | |
| Denise Dowse | 1 | |
| Stephen Lee | 1 | |
| Richard Cox | 1 | |
| Michole Briana White | 1 | |
| Jesse Burch | 1 | |
| Austin Majors | Kid | 1 |
| Shane Conrad | 1 | |
| Deborah Strang | 1 | |
| Ewan Chung | 1 | |
| Matt Corboy | 1 | |
| Tanner Richie | 1 |