Katsutoshi Nagasawa (長沢 勝俊 Nagasawa Katsutoshi, August 2, 1923 – January 10, 2008) was a Japanese composer of classical music with a modern approach. Nagasawa composed for traditional Japanese musical instruments (e.g., Shakuhachi, Koto, Shamisen).
Nagasawa was born in 1923 in Tokyo and graduated from Nihon University. He was one of the founding members of Pro Musica Nipponia (日本音楽集団) in 1964, a group of famous Japanese composers and musicians who aim at performing classical and contemporary compositions from both Japan and the West. The groups music is performed by traditional Japanese musical instruments.