Kuroiwa (黒岩) is a Japanese family name meaning 'black stone'. Notable people with the surname include:
Akira Kuroiwa (born 1961), a Japanese ice speed skater
Hisami Kuroiwa, Japanese film producer
Mamoru Kuroiwa (born 1962), a Japanese Olympic boxer
Shuroku Kuroiwa, also known as Ruikō Kuroiwa, a Japanese journalist and novelist
Toshio Kuroiwa, a Japanese military pilot who was stationed on Japanese aircraft carrier Kaga
Toshiyuki Kuroiwa (born 1969), a Japanese ice speed skater
Yoshihiro Kuroiwa, a manga artist on Zenki
Fictional characters:
Geki Kuroiwa, a character in the Japanese anime series Brave Command Dagwon