An automotive rotary electric machine comprising a stator comprising: an annular stator core in which a plurality of slots that have openings on an inner circumferential side are disposed at a predetermined pitch circumferentially; and a stator winding that is constituted by a plurality of winding assemblies that are mounted into said stator core, wherein said winding assemblies are configured by arranging wire pairs that are equal in number to a predetermined slot pitch so as to be offset from each other by a pitch of one slot, said wire pairs being formed by arranging two wires so as to be offset by said predetermined slot pitch from each other such that slot-housed portions are stacked, said wires being constituted by continuous wires that are formed into a pattern in which said slot-housed portions are linked by return portions and are arranged at said predetermined slot pitch, and adjacent slot-housed portions are offset by said return portions so as to alternately occupy an inner layer and an outer layer in a slot depth direction, and said slot-housed portions are plastically deformed so as to have a squared cross section; said stator winding is configured by mounting said winding assemblies into said stator core so as to be stacked in three or more layers in a radial direction such that said slot-housed portions line up in single columns in a slot depth direction inside said slots; and characterized in that radial widths of said return portions of said winding assemblies that are mounted so as to be stacked in a radial direction are made sequentially narrower in order of return portions of a winding assembly that is positioned centrally, return portions of a winding assembly that is positioned on an inner circumferential side, and return portions of a winding assembly that is positioned on an outer circumferential side. an annular stator core in which a plurality of slots that have openings on an inner circumferential side are disposed at a predetermined pitch circumferentially; and a stator winding that is constituted by a plurality of winding assemblies that are mounted into said stator core, wherein said winding assemblies are configured by arranging wire pairs that are equal in number to a predetermined slot pitch so as to be offset from each other by a pitch of one slot, said wire pairs being formed by arranging two wires so as to be offset by said predetermined slot pitch from each other such that slot-housed portions are stacked, said wires being constituted by continuous wires that are formed into a pattern in which said slot-housed portions are linked by return portions and are arranged at said predetermined slot pitch, and adjacent slot-housed portions are offset by said return portions so as to alternately occupy an inner layer and an outer layer in a slot depth direction, and said slot-housed portions are plastically deformed so as to have a squared cross section; said stator winding is configured by mounting said winding assemblies into said stator core so as to be stacked in three or more layers in a radial direction such that said slot-housed portions line up in single columns in a slot depth direction inside said slots; and characterized in that radial widths of said return portions of said winding assemblies that are mounted so as to be stacked in a radial direction are made sequentially narrower in order of return portions of a winding assembly that is positioned centrally, return portions of a winding assembly that is positioned on an inner circumferential side, and return portions of a winding assembly that is positioned on an outer circumferential side.