Tsutsui (written: 筒井 meaning "round well") is a Japanese surname. Notable people with the surname include:
Hajime Tsutsui (筒井 はじめ, born 1970), Japanese artistTsutsui Jōmyō Meishū (筒井 浄妙 明秀), Japanese warrior monkTsutsui Junkei (筒井 順慶, 1549–1584), Japanese daimyōTsutsui Junshō (筒井 順昭, 1523–1550), Japanese daimyōKazuya Tsutsui (筒井 和也, born 1981), Japanese baseball playerMihoko Tsutsui (筒井 視穂子, born 1985), Japanese volleyball playerNobutaka Tsutsui (筒井 信隆, born 1944), Japanese politicianNoriaki Tsutsui (筒井 紀章, born 1976), Japanese footballerRyohei Ron Tsutsui (born 1977), Japanese film producerTsutsui Sadatsugu (筒井 定次, 1562–1615), Japanese samuraiShan Tsutsui (born 1971), American politicianWilliam Tsutsui, American academicYasutaka Tsutsui (筒井 康隆, born 1934), Japanese writer and actor