Nittatsu Hosoi (細井日達, Hosoi Nittatsu; April 15, 1902, Tokyo - June 22, 1979) was the 66th high priest of Nichiren Shoshu, a major school of Nichiren Buddhism, and chief priest of its head temple Taisekiji in Fujinomiya, Shizuoka, Japan. He was succeeded by Nikken Abe after his death.