|Birth name||椙山 浩一|
|Born||April 11, 1931|
Tokyo, Empire of Japan
|Died||September 30, 2021 (aged 90)|
|Associated acts||Hayato Matsuo|
Koichi Sugiyama (すぎやま こういち, Sugiyama Kōichi, April 11, 1931 – September 30, 2021) was a Japanese composer, conductor, and orchestrator. He is known for composing the music for the Dragon Quest series.
Sugiyama was also a council member of the Japanese Society for Rights of Authors, Composers, and Publishers (JASRAC), board member of the Japan Institute for National Fundamentals, and honorary chairman of the Japanese Backgammon Society.