| Tadashi Otsuka | |
| Birth Date: | 30 April 1978 |
| Birth Place: |  Nagasaki |
| Event: | Men's Doubles |
| Handedness: | Right |
| Current Ranking: | 9 |
| Date Of Current Ranking: | September 25, 2008 |
| Bwf Id: | 73051006-630F-436D-AEB2-1162CAEB4BA1 |
is a male badminton player from Japan.
Otsuka competed in badminton at the 2004 Summer Olympics in men's doubles with partner Keita Masuda. They had a bye in the first round, then were defeated in the round of 16 by Fu Haifeng and Cai Yun of China.He also competed in mixed doubles with partner Shizuka Yamamoto. They were defeated in the round of 32 by Robert Blair and Natalie Munt of Great Britain.
Ohtsuka played at the 2007 BWF World Championships in men's doubles with Keita Masuda, and were defeated in the third round by the eventual champions Markis Kido and Hendra Setiawan, of Indonesia, 22-20, 21-19.