Knocking or Knockin or Knockin' may refer to:
Knocking (2006 film), a documentary about Jehovah's Witnesses Knocking (2021 film), a Swedish thriller film Engine knocking, or the sound accompanying automotive combustion malfunction Port knocking, a covert method of opening a port on a server Roof knocking, a bombing practice of the Israeli Defense Forces Gene knockin, genetic engineering method Knockin Castle, castle situated in the village of Knockin on Shropshire between Oswestry and Shrewsbury Knocking, Austria, a hamlet, subdivision of Erlauf (municipality) in Austria "Knockin'", a 1995 song by Spanish band Double Vision "Knockin", a 2025 song by Mac DeMarco from Guitar
See also Knock (disambiguation) Knockin' on Heaven's Door (disambiguation) The Knocking, a 2022 Finnish horror film