Sasaki Kojirō (佐々木 小次郎, also known as Ganryū Kojirō) (c. 1575 – April 13, 1612), often anglicised to Kojirō Sasaki, was a prominent Japanese swordsman widely considered a master of his craft, born in Fukui Prefecture. He lived during the Azuchi–Momoyama and early Edo periods and is most remembered for his death while battling Miyamoto Musashi in 1612.