| Character | Actor |
|---|---|
| James T. Kirk | William Shatner |
| Spock | Leonard Nimoy |
| Leonard McCoy | DeForest Kelley |
| Nyota Uhura | Nichelle Nichols |
| Montgomery Scott | James Doohan |
| Hikaru Sulu | George Takei |
| Pavel Chekov | Walter Koenig |
Recurring Characters
| Character | Actor |
|---|---|
| Christopher Pike | Jeffrey Hunter |
| Number One | Majel Barrett |
| Sarek | Mark Lenard |
| Amanda Grayson | Jane Wyatt |
| Scotty | James Doohan |
| Uhura | Nichelle Nichols |
| Chekov | Walter Koenig |
| Sulu | George Takei |
Guest Stars
| Character | Actor |
|---|---|
| The Gorn Captain | Bill Erwin |
| Lt. Janice Rand | Grace Lee Whitney |
| Lt. Ayelborne | David Soul |
| Lt. Leslie | Eddie Paskey |
| Lt. DeSalle | Michael Ansara |
| Lt. Commander McGivers | Ron Howard |
| Lt. Riley | Michael Forest |
| Commander Kor | John Colicos |
| Kang | Michael Ansara |
| Kodos the Executioner | Leonard Nimoy |
| Khan Noonien Singh | Ricardo Montalbán |
| Harry Mudd | Roger C. Carmel |
| Sylvia Tilly | Mary Wiseman |
| Michael Burnham | Sonequa Martin-Green |
| Ash Tyler | Shazad Latif |
| Paul Stamets | Anthony Rapp |
| Jett Reno | Tig Notaro |
Additional Characters
| Character | Actor |
|---|---|
| Yeoman Rand | Grace Lee Whitney |
| Nurse Chapel | Majel Barrett |
| Ensign Chekhov | Walter Koenig |
| Ensign Sulu | George Takei |
| M'Benga | Booker Bradshaw |
| Arex | Ted Cassidy |
| Balok | Clint Howard |
| Elaan of Troyius | France Nuyen |
| Leila Kalomi | Majel Barrett |
| Losira | Susan Oliver |
| Miramanee | Barbara Luna |
| Shahna | Yvonne Craig |
| Vina | Susan Oliver |
| Zarabeth | Marj Dusay |