"Plato's Stepchildren" is the tenth episode of the third season of the original science fiction television series, Star Trek, first broadcast November 22, 1968. It is episode No. 65, production No. 67, written by Meyer Dolinsky, and directed by David Alexander. This episode is notable for depicting an inter-racial kiss between a white man (Kirk) and a black woman (Uhura), which was daring for 1960s US television.

In this episode, the crew of the Enterprise encounters an ageless and sadistic race of humanoids with the power of telekinesis and who claim to have organized their society around Ancient Greek ideals.

Captain Kirk, along with First Officer Spock and Chief Medical Officer Dr. McCoy beam down to a planet (rich in rare "kironide" mineral deposits) to investigate a distress call.

Once there, they are greeted by a friendly dwarf named Alexander (Michael Dunn), who leads the landing party to meet the rest of his people, who have adopted classical Greek culture, and named themselves Platonians in honor of the Greek philosopher Plato. All of the Platonians, except for Alexander, seem to possess telekinetic powers. (Later, it is determined one of the biochemical effects of Alexander's dwarfism is the inability to make use of the kironide.)

The Platonians explain they "lured" the Enterprise to their planet because their leader, Parmen, requires medical help. After being treated by Dr. McCoy, Parmen demands McCoy remain on the planet to treat other Platonians. When Captain Kirk objects, the Platonians use their powers to punish him. They arrogantly humiliate Kirk and Spock as Dr. McCoy watches, forcing them to sing and dance like court jesters. Parmen forces Spock to laugh and, despite the strong objection of Dr. McCoy, to cry. Later, the Platonians use their powers to force two other Enterprise officers to the planet for their entertainment: Communications Officer Lt. Uhura and Nurse Chapel.

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