The Menagerie is an episode of the original Star Trek series.

The 1966 episode was the only two-part story ever made for the original show. It is considered by some fans to be the pilot episode (if not the most popular episode in the entire original series), even though the bulk of the episode is derived from the original unsold pilot, The Cage.

After the failure of The Cage and the eventual sale of the series to NBC due to the second pilot, Where No Man Has Gone Before, Desilu (the show's producer) decided what should be done with the unused pilot. Gene Roddenberry declared that in order to utilize the Cage footage, he would write an entirely new bookending story, thus now The Cage would serve as a backstory for the Starship Enterprise's early history. The new footage would have Mr. Spock on trial for kidnapping a now-incapacitated Captain Christopher Pike and locking the Enterprise on a course for Talos IV (now forbidden due to events depicted in The Cage) and facing a death penalty (per the Federation's General Order #7 preventing contact with Talos).

Since Jeffrey Hunter was unavailable to reprise his role as Captain Pike, lookalike actor Sean Kenney played the injured captain in the new scenes, although Hunter was represented in the Cage flashback footage and credited accordingly (along with the original Cage cast). Also in the new scenes, Malachi Throne (who played the Keeper in the original Cage) portrayed Commodore Joe Mendez, while Julie Parrish played personal assistant Miss Piper. Because Throne played a second role in The Menagerie, another actor dubbed in The Keeper's original lines (which had been voiced in The Cage by Throne).

The footage from The Cage that was edited into the final master negative of The Menagerie was taken from what was thought to be the only color print of the original pilot. Years later, a full-color print of the complete Cage was discovered in Paramount's archives.

The Menagerie won a Hugo Award for Best Television Sci-Fi Program.