Episodes are sorted by production date, not air date.

1.01  Where No Man Has Gone Before

1.02  The Corbomite Maneuver

1.03  Mudd’s Women

1.04  The Enemy Within

1.05  The Man Trap

1.06  The Naked Time

1.07  Charlie X

1.08  Balance of Terror

1.09  What Are Little Girls Made Of?

1.10  Dagger of the Mind

1.11  Miri

1.12  The Conscience of the King

1.13  The Galileo Seven

1.14  Court Martial

1.15  The Menagerie, Part I

1.16  The Menagerie, Part II

1.17  Shore Leave

1.18  The Squire of Gothos

1.19  Arena

1.20  The Alternative Factor

1.21 Tomorrow Is Yesterday

1.22 The Return of the Archons

1.23 A Taste of Armageddon

1.24 Space Seed

1.25 This Side of Paradise

1.26 The Devil in the Dark

1.27 Errand of Mercy

1.28 The City on the Edge of Forever

1.29 Operation — Annihilate!

Season 2 | Season 3 | Behind the Scenes