TDK(Tokyo Denkikagaku Kogyo K.K.) is a company that manufactures electronic materials, electronic components, and recording and data-storage media. It was founded in Japan in 1935 to manufacture ferrite, which had been recently invented by Yogoro Kato. As of June 1998, Hiroshi Sato retired and appointed Hajime Sawabe as president. See TDK Corporation.

Also, TDK (Turk Dil Kurumu) is the initialism of Turkish Language Association .