- Ep: 1
- Beyond the Farthest Star
- Written By: Samuel A. Peeples
- Directed By: Hal Sutherland
- Ep: 2
- Yesteryear
- Uncredited: Mark Lenard (Sarek), Billy Simpson (Young Spock), Keith Sutherland (Young Sepek)
- Written By: D.C. Fontana
- Directed By: Hal Sutherland
- Ep: 3
- One of Our Planets is Missing
- Written By: Marc Daniels
- Directed By: Hal Sutherland
- Ep: 4
- The Lorelei Signal
- Written By: Margaret Armen
- Directed By: Hal Sutherland
- Ep: 5
- More Tribbles, More Troubles
- Uncredited: Stanley Adams (Cyrano Jones), David Gerrold (Korax)
- Written By: David Gerrold
- Directed By: Hal Sutherland
- Ep: 6
- The Survivor
- Uncredited: Ted Knight (Carter Winston)
- Written By: James Schmerer
- Directed By: Hal Sutherland
- Ep: 7
- The Infinite Vulcan
- Written By: Walter Koenig
- Directed By: Hal Sutherland
- Ep: 8
- The Magicks of Megas-Tu
- Uncredited: Ed Bishop (Asmodeus)
- Written By: Larry Brody
- Directed By: Hal Sutherland
- Ep: 9
- Once Upon a Planet
- Written By: Chuck Menville & Len Janson
- Directed By: Hal Sutherland
- Ep: 10
- Mudd's Passion
- Uncredited: Roger C. Carmel (Harry Mudd)
- Written By: Stephen Kandel
- Directed By: Hal Sutherland
- Ep: 11
- The Terratin Incident
- Written By: Paul Schneider
- Directed By: Hal Sutherland
- Ep: 12
- The Time Trap
- Written By: Joyce Perry
- Directed By: Hal Sutherland
- Ep: 13
- The Ambergris Element
- Uncredited: David Gerrold (Nephro)
- Written By: Margaret Armen
- Directed By: Hal Sutherland
- Ep: 14
- The Slaver Weapon
- Written By: Larry Niven
- Directed By: Hal Sutherland
- Ep: 15
- The Eye of the Beholder
- Written By: David P. Harmon
- Directed By: Hal Sutherland
- Ep: 16
- The Jihad
- Uncredited: David Gerrold (Em-3-Green)
- Written By: Stephen Kandel
- Directed By: Hal Sutherland
| William Shatner ............... Captain James Kirk |
| Leonard Nimoy .................... Commander Spock |
| DeForest Kelley ................ Dr. Leonard McCoy |
| George Takei ..................... Lieutenent Sulu |
| Nichelle Nichols ................ Lieutenent Uhura |
| Majel Barrett ... Nurse Chapel / Lieutenant M'Ress |
| James Doohan .... Engineer Scott / Lieutenant Arex |
