Kusaka (written: 日下 or 草鹿) is a Japanese surname. Notable people with the surname include:
Chihiro Kusaka (日下 ちひろ) (born 1978), Japanese voice actressHidenori Kusaka (日下 秀憲), Japanese manga artistJinichi Kusaka (草鹿 任一) (1888–1972), Imperial Japanese Navy admiralMaryanne Kusaka, American politicianRyūnosuke Kusaka (草鹿 龍之介) (1893–1971), Imperial Japanese Navy admiralShin Kusaka (日下 慎), Japanese actorTakeshi Kusaka (日下 武史) (born 1931), Japanese actor and voice actor