Provided are a steel sheet for battery outer tube cans, which is used for an aftergilding method and is suppressed in the occurrence of scratches, and which enables the achievement of a battery outer tube can that has excellent corrosion resistance and buckling resistance; and a battery outer tube can and a battery, each of which uses this steel sheet for battery outer tube cans. This steel sheet for battery outer tube cans has an Fe—Ni diffusion layer on both surface layers of a steel sheet; the Nb content in the steel sheet is from 0.010% by mass to 0.050% by mass (inclusive); and the adhesion amount of the Fe—Ni diffusion layer per one surface of the steel sheet is from 50 mg/m2 to 500 mg/m2 (inclusive) in terms of Ni.