There are provided a rotating member assembly and a spindle motor including the same. The rotating member assembly includes: a rotating member including a shaft and a hub fixed to an upper portion of the shaft, wherein perpendicularity of the hub with regard to the shaft at a position spaced apart from the center of rotation of the shaft in an outer diameter direction by an axial length or more for which the shaft is fitted into the sleeve is less than double a distance of a gap of a bearing clearance formed by fitting the shaft into the sleeve.