TDK Corporation is a Japanese electronics manufacturer.
TDK may also refer to:
- TDK Australian Audio Book Awards
- Team Dragon Knights, a disbanded League of Legends team
- TDK Electronics, a German subsidiary of TDK Corporation
- Mark Knight (musician)
- The Dark Knight, 2008 superhero film directed by Christopher Nolan
- The Detachable Kid, a character from the 2021 film The Suicide Squad
- Turkish Language Association (Turkish: Türk Dil Kurumu or TDK), official authority
- TDK SC, a Japanese football team
- TDK, the IATA airport code for Taldykorgan Airport, Kazakhstan