Knock Knock (disambiguation)

Knock Knock may refer to:
==In-universe==
*Knock-knock jokes (PROSE: Knock! Knock! Who's There?)
==Out-of-universe==
*Knock Knock! by Paul Magrs, a short story published in the Doctor Who Storybook 2010
*Knock Knock, a 2015 episode of Doctor Who Series 10
*Knock! Knock! Who's There?, a 2020 children's joke book