John Ritter (1948–2003) was an American actor.
John Ritter may also refer to: John Ritter (congressman) (1779–1851), American legislator from Pennsylvania John Ritter (racing driver) (1910–1948), American racing driver John H. Ritter (born 1951), American novelist, short story writer, teacher, and lecturer John D. Ritter, vocalist for American metalcore band Myka Relocate John Steele Ritter, American classical keyboardist and teacher John Ritter (rugby union), Australian international rugby union player
See also Johann Wilhelm Ritter (1776–1810), German chemist, physicist and philosopher