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