TDK is a Japanese electronics manufacturer. It may also refer to:
- TDK Australian Audio Book Awards
- Turkish Language Association, (Türk Dil Kurumu - TDK) the regulatory body of the Turkish language
- The Dark Knight
- Team Dragon Knights, professional League of Legends team
- Team DK
, formerly , is a Japanese multinational electronics company that manufactures electronic materials, electronic components, and recording and data-storage media. They are best known for having been the leading manufacturer of compact cassettes. Its motto is "Contribute to culture and industry through creativity".
TDK is listed on the Tokyo Stock Exchange and is a constituent of the Nikkei 225 and TOPIX indices.