Kaji is a Japanese surname. Notable persons with that name include:
Akira Kaji (born 1980), Japanese footballerMaki Kaji (born 1951), Japanese businessmanMasaki Kaji (born 1988), Japanese actor and singerMeiko Kaji (born 1947), Japanese actress and singerRyuichi Kaji (1896–1978), Japanese journalist and political criticShungo Kaji (born 1961), Japanese film director, screenwriter, producer and company executiveWataru Kaji (1903–1982), Japanese writerYūki Kaji (born 1985), Japanese voice actor