Takashi Nagai (?? ?, Nagai Takashi, February 3, 1908, Matsue – May 1, 1951, Nagasaki) was a physician specializing in radiology, a convert to Roman Catholicism, and a survivor of the atomic bombing of Nagasaki. His subsequent life of prayer and service earned him the affectionate title "saint of Urakami" and has subsequently been honoured with the title Servant of God, the first step towards the Roman Catholic sainthood.