A rotor blade includes: a blade main body having a tip as an upstream end in a rotation direction, and a blade surface in contact with the tip and which is an upstream surface in a flow direction of a work fluid; and an erosion shield formed as a cladding portion using laser welding on the tip and the blade surface. A boundary between the blade main body and the erosion shield is shaped to approach a surface opposite the blade surface from an end facing the blade surface towards the tip. The boundary includes a first arc that includes the end facing the blade surface and a second arc closer towards the tip than the first arc. The first arc is convex towards an inside of the blade main body and the second arc is convex towards an outside of the blade main body.