An oxide superconducting wire includes a superconductor laminate including an oxide superconducting layer on at least one surface of a base material, and a plating layer which is included in a stabilizing layer of the superconductor laminate and formed by plating. A surface roughness Ra of the plating layer is 1.0 μm or more and 2.0 μm or less. An entire average crystal grain size of the plating layer is 0.86 μm or more and 3.05 μm or less.