The season(s) during which each actor has been included in the main cast are marked in black. When a starring actor also has appeared as a guest star during other seasons, this is marked in gray, with the number of guest appearances noted in italics. White square means the actor doesn’t appear in that season at all.
Series Regulars
| Actor(s) | Character | Appearances | |||||
|---|---|---|---|---|---|---|---|
| S 1 | S 2 | S 3 | S 4 | ||||
| Joel Gretsch | Tom Baldwin | ||||||
| Jacqueline McKenzie | Diana Skouris | ||||||
| Mahershalalhashbaz Ali | Richard Tyler | 2 | |||||
| Patrick Flueger | Shawn Farrell | ||||||
| Conchita Campbell | Maia Skouris | ||||||
| Chad Faust | Kyle Baldwin | 3 | |||||
| Laura Allen | Lily Tyler | 1 | |||||
| Kaj-Erik Eriksen | Danny Farrell | 7 | 1 | 3 | |||
| Brooke Nevin | Nikki Hudson | 1 | 1 | ||||
| Peter Coyote | Dennis Ryland | 2 | 5 | ||||
| Samantha Ferris | Nina Jarvis | ||||||
| Karina Lombard | Alana Mareva | 5 | |||||
| Megalyn Echikunwoke | Isabelle Tyler | (8) | |||||
| Billy Campbell | Jordan Collier | 3 | 6 | 4 | |||
| Jenni Baird | Meghan Doyle | ||||||
Recurring Guest Stars
| Actor(s) | Character | Appearances | |||||
|---|---|---|---|---|---|---|---|
| S 1 | S 2 | S 3 | S 4 | ||||
| Richard Kahan | Marco Pacella | 3 | 9 | 9 | 11 | ||
| Natasha Gregson Wagner | April Skouris | 5 | 3 | 1 | |||
| Jeffrey Combs | Kevin Burkhoff | 5 | 6 | 6 | |||
| Kavan Smith | Jed Garrity | 7 | 9 | 6 | |||
| Summer Glau | Tess Doerner | 2 | 3 | 4 | |||
| Jody Thompson | Devon Moore | 4 | 10 | 1 | |||
| Garret Dillahunt | Matthew Ross | 6 | 5 | ||||
| Tristin Leffler | Cassie Dunleavy | 8 | |||||