A bus bar assembly includes a bus bar holder and bus bars each including a main line portion extending in a plane perpendicular or substantially perpendicular to a center axis in a posture in which a plate surface is oriented in an axial direction, and a connection terminal portion connected to an end portion of the main line portion. When viewed in the axial direction as a symmetry axis, the main line portion of the first U-phase bus bar and the main line portion of the second U-phase bus bar, the main line portion of the first V-phase bus bar and the main line portion of the second V-phase bus bar, and the main line portion of the first W-phase bus bar and the main line portion of the second W-phase bus bar, each have a shape line-symmetric to each other.