| Name | Character | Episodes |
|---|---|---|
| Dane Clark | Dan Miller | 35 |
| Mercedes McCambridge | Kate Wells | 35 |
| George Brent | Dean Evans | 35 |
| Parley Baer | Wallace | 2 |
| Peter Baldwin | Paul Johnston / Hal Johnston | 2 |
| Charles Bronson | Sam Adams | 1 |
| Michael Landon | Pietro | 1 |
| Leslie Phillips | Keynes | 1 |
| Diane Brewster | Mary | 1 |
| Andrew Duggan | Stowe | 1 |
| Scott Marlowe | Ricci | 1 |
| Vladimir Sokoloff | Prime Minister | 1 |
| Anthony Caruso | Arturo | 1 |
| Carolyn Jones | Eve | 1 |
| Lee Van Cleef | Al Sanders | 1 |
| Adam Williams | Wells | 1 |
| Virginia Gregg | Marie | 1 |
| Virginia Gregg | Nora | 1 |
| Gene Evans | (uncredited) | 1 |
| Murray Hamilton | Ed Holley | 1 |
| Murray Hamilton | Frank Lunt | 1 |
| Douglas Spencer | Mason | 1 |
| Beverly Garland | Elaine Rath | 1 |
| Beverly Garland | Ellen Gale | 1 |
| Paul Fix | Thompson | 1 |
| Edd Byrnes | Bob | 1 |
| Paul Richards | Hank Barclay | 1 |
| Harry Carey, Jr. | Steve Ward | 1 |
| Jay Robinson | Rod Usher | 1 |
| Carleton Young | Warden | 1 |
| Ray Teal | Captain Gormand | 1 |
| Howard McNear | Caldwell | 1 |
| H.M. Wynant | Johnny Dukes | 1 |
| Ian Wolfe | Father Rambeau | 1 |
| Jimmy Lydon | Harris | 1 |
| Rebecca Welles | Julia Thomas | 1 |
| Eduardo Noriega | Murillo | 1 |
| Dayton Lummis | Amos Fairchild | 1 |
| Werner Klemperer | Krylov | 1 |
| George Pravda | Visitor | 1 |
| Malcolm Atterbury | Gil Venton | 1 |
| Malcolm Atterbury | 1 | |
| Lawrence Dobkin | Mr. March | 1 |
| Robert Beatty | John Templar | 1 |
| Royal Dano | Carl Strawn | 1 |
| Vaughn Taylor | Hugh Saxton | 1 |
| Michael Pate | Edward Lansing | 1 |
| Anton Diffring | Joseph Tezlik | 1 |
| Don Beddoe | Raisner | 1 |
| Arthur Hunnicutt | Hopeful | 1 |
| Louis Jean Heydt | Benton | 1 |
| Fay Spain | Peggy | 1 |
| Barton MacLane | Gen. Bailey | 1 |
| Marjorie Lord | Phyllis Holley | 1 |
| Phillip Pine | Marty Ryan | 1 |
| Robert Hutton | Hannon | 1 |
| Phillip Terry | Phillip Tennant | 1 |
| John Smith | Howie | 1 |
| Herbert Rudley | Lt. Stanley | 1 |
| Harry Shannon | Harris Ellerby | 1 |
| Ross Elliott | Roger Rath | 1 |
| Anthony Eustrel | Condell | 1 |
| Whitney Blake | Geraldine | 1 |
| Harry Townes | Montago | 1 |
| John Beradino | Pallavicino | 1 |
| Larry Pennell | Johnny Westrup | 1 |
| Clifford Evans | Air Marshal Fraylie | 1 |
| Edward Platt | Palmer | 1 |
| Russell Napier | Admiral Habberfield | 1 |
| Peter Illing | Otto | 1 |
| Shepperd Strudwick | David | 1 |
| Margaret Hayes | Mary Carberry | 1 |
| Donald Randolph | 1 | |
| Eve Miller | Dolly Johnson | 1 |
| Richard Caldicot | Lord Belding | 1 |
| Victor Millan | Peres | 1 |
| Barbara Bestar | 1 | |
| John Alvin | Chief Dispatcher | 1 |
| Stuart Randall | Lt. Patch | 1 |
| Brian Oulton | Denver | 1 |
| Ann Codee | Cecile | 1 |
| Seymour Green | Reception Clerk | 1 |
| Rhodes Reason | Huntley | 1 |
| George Chandler | Hoggard | 1 |