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.
Sugiyama died on September 30, 2021 from sepsis in Tokyo at the age of 90.[1]