Otokosaburo Noguchi (né Otokosaburo Takebayashi; 1880 – July 2, 1908) was a Japanese murderer and suspected serial killer who was convicted of killing a drug store owner in 1905, and was the prime suspect in two other murders dating back to 1902. Sentenced to death for the only murder he was convicted of, he was subsequently hanged at Ichigaya Prison.