Theatre 625 is a British television drama anthology series, produced by the BBC and transmitted on BBC2 from 1964 to 1968. It was one of the first regular programmes in the line-up of the channel, and the title referred to its production and transmission being in the higher-definition 625-line format, which only BBC2 used at the time.

Two carnies (Sewell and Gugino) abduct a mermaid in Ireland, circa 1900, and decide to transport her to America. As their ship loses its way and heads towards the mythical Forbidden Islands, the mermaid begins to display its deadly side.

The shooting of a U.S. senator's wife raises the stakes for kidnappers seeking a hefty ransom for a computer magnate.

Robert, a chemist, experiments on himself with a new drug that has an unexpected side-effect: it turns Robert into a woman whenever he gets sexually aroused!

Unemployed East End lad Alf Hitchens has an on-off relationship with his girlfriend Marilyn and a dream of hitting the big time in the music business. Cheerful pop musical with a working-class background which uses a number of genuine London locations.