Sasaki Kojiro (??? ???, also known as Sasaki Ganryu) (c.?1585 – April 13, 1612), often anglicised to Kojiro 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.