| Name | Character | Episodes |
|---|---|---|
| John Corbett | Adam MacArthur | 13 |
| Leon Rippy | Agent Nicholas LaRu | 13 |
| Steve Railsback | Colonel James Vise | 13 |
| Grand L. Bush | Agent Douglas Wilcox | 13 |
| John Storey | Agent Craig Van Patten | 13 |
| Granville Ames | Sgt. Roberts | 5 |
| Adam Baldwin | Michael O'Ryan | 4 |
| Richard Cox | Asst. Director Grushaw | 4 |
| Tammy Lauren | Charlotte MacArthur | 2 |
| Lola Glaudini | Constance MacArthur | 2 |
| Lucinda Jenney | Nadine Walden | 2 |
| David Drew Gallagher | McNally | 2 |
| Amy Parrish | Betty York | 2 |
| Alonzo Bodden | Lt. Warren Reed | 2 |
| Robert Knepper | Alex Burton | 1 |
| Wendy Worthington | Female Shadow | 1 |
| Rachel Winfree | Nurse | 1 |
| Chris Ufland | Soldier | 1 |
| Paul Terrell Clayton | Military Policeman | 1 |
| Rosemary Murphy | Tour Guide | 1 |
| John Carroll Lynch | Joe York | 1 |
| Barbara Bain | Constance MacArthur | 1 |
| Jessica Tuck | Lawson | 1 |
| Adam Baldwin | Michael O'Ryan / Joe York | 1 |
| Richard Riehle | Principal Shinagel | 1 |
| Harry Shearer | Louis Faraday | 1 |
| Matt Clark | Monroe | 1 |
| Michael Harney | Warden Burke | 1 |
| Sam Anderson | Army General | 1 |
| Bruce French | Father Traylor | 1 |
| Tony Amendola | Thomas | 1 |
| Charles Hallahan | Sheriff | 1 |
| Dianne Turley Travis | Dr. Pauline Greenfield | 1 |
| Jill Remez | Dr. Patricia Ryan | 1 |
| Paul Raci | Dark Grey Suit | 1 |
| Jackie Debatin | Louise | 1 |
| Wendy Gazelle | Ruth Burton | 1 |
| Judy Kain | Nurse | 1 |
| Mary Carver | Winifred Quick | 1 |
| Efrem Zimbalist Jr. | Wayland Scott | 1 |
| John Kassir | 1 | |
| Steve Monroe | Steven | 1 |
| Travis Wester | Young Vise | 1 |
| Lori Heuring | Laura Scott | 1 |
| Conrad Bachmann | Male Shadow | 1 |
| Ellen Bry | ER Doctor | 1 |
| Eve Brenner | Hospital Administrator | 1 |
| Mary Mara | Magnolia Vale | 1 |
| Charles Rahi Chun | Satcom Officer | 1 |
| Shaun Toub | 1 | |
| Darwyn Carson | ER Nurse | 1 |
| Glenn Taranto | FBI Agent | 1 |
| Dennis Burkley | Louie | 1 |
| Sam Gifaldi | Stephen Burton | 1 |
| Nicolas Surovy | Ben Proctor | 1 |
| Michael Bacall | Carlo | 1 |
| Courtney Peldon | Donna | 1 |
| Scott Shaw | James (uncredited) | 1 |
| Bill Morey | Henry Milton | 1 |
| Sandra Thigpen | Security Guard | 1 |
| Richard Hamilton | Captain | 1 |
| Larissa Laskin | Katherine | 1 |
| Jack Rader | Randall Craig | 1 |
| Turhan Bey | Rusha | 1 |
| Diana Bellamy | Mother | 1 |
| Michael O'Hagan | Dr. Howard Stein | 1 |
| Vanessa Zima | Melissa | 1 |
| Mowava Pryor | NSA Agent | 1 |
| Steven Anderson | Doctor | 1 |
| George Sullivan | NSA Superior | 1 |
| Cynthia Mace | Congresswoman Wagstaff | 1 |
| Jack Moore | Soldier #1 | 1 |
| Frank Gerrish | Sheriff Newsom | 1 |
| Stephen Berra | Danny | 1 |
| Teddy Lane Jr. | Cop | 1 |
| Fred Pinkard | Beauregard Wilde | 1 |
| Rob Elk | Father | 1 |
| Walter Olkewicz | Ozzie Faulkner | 1 |
| Chuck Sloan | Danny's Father | 1 |
| Dominic Oliver | Benny | 1 |