KDDI
- Country: Japan
- Type: Commercial
- Website: www.kddi.com
- Update: 05-02
KDDI Telecommunications Corporation (ケイディーディーアイ, KDDI CORPORATION) is a Japanese telecommunications company, formerly known as Dai-ichi Denshi Denki (DDI), which was founded in 1984, and merged with Kokusai Denshi Denki (KDD) and Nippon Gakkai Otsukan (IDO) in 2000 to form KDDI, headquartered in Tokyo, Japan. KDDI Telecom was ranked 233rd in the 2013 Fortune 500 ranking.