The Rump Parliament was the English Parliament after Colonel Thomas Pride purged the Long Parliament, on 6 December 1648, of those members hostile to the Grandees' intention to try King Charles I for high treason.

"Rump" normally means the hind end or back-side of a mammal; its use meaning "remnant" was first recorded in the above context in English. Since 1649, the term "rump parliament" has been used to refer to any parliament reduced in size from its legitimate predecessor.