A twisted wire conductor for an insulated electrical wire, the twisted wire conductor being configured to be in a mixed state in which first conductors and second conductors are twisted together, the first conductors comprising a specific aluminum alloy having an alloy composition containing, by mass%, 0.2% to 1.8% of Mg, 0.2% to 2.0% of Si, 0.01% to 0.33% of Fe, and 0.00% to 2.00% in total of one or more elements selected from the group consisting of Cu, Ag, Zn, Ni, Co, Au, Mn, Cr, V, Zr, Ti, and Sn, with the remainder being Al and unavoidable impurities, the specific aluminum alloy having a fibrous metal structure in which crystal grains extend to be aligned in one direction, and in a cross-section parallel to the one direction, an average value of a dimension perpendicular to a longitudinal direction of the crystal grains is 400 nm or less; and the second conductors comprising a metal or an alloy selected from the group consisting of copper, copper alloy, aluminum, and aluminum alloy, and having higher electrical conductivity than the first conductors, wherein when viewed from a transverse cross-section of the twisted wire conductor, a proportion B1 occupied by the number of first conductors in the total number of first conductors and second conductors, which are positioned in an outermost layer of the twisted wire conductor, is higher than a proportion A occupied by the number of first conductors in the total number of first conductors and second conductors constituting the twisted wire conductor or the proportion B2 occupied by the number of first conductors in the total number of first conductors and second conductors, which are positioned within a region partitioned by a virtual circle that is concentric with a circumscribed circle of the twisted wire conductor and has a radius equal to a half of a radius of the circumscribed circle, is higher than the proportion A occupied by the number of first conductors in the total number of first conductors and second conductors constituting the twisted wire conductor. the first conductors comprising a specific aluminum alloy having an alloy composition containing, by mass%, 0.2% to 1.8% of Mg, 0.2% to 2.0% of Si, 0.01% to 0.33% of Fe, and 0.00% to 2.00% in total of one or more elements selected from the group consisting of Cu, Ag, Zn, Ni, Co, Au, Mn, Cr, V, Zr, Ti, and Sn, with the remainder being Al and unavoidable impurities, the specific aluminum alloy having a fibrous metal structure in which crystal grains extend to be aligned in one direction, and in a cross-section parallel to the one direction, an average value of a dimension perpendicular to a longitudinal direction of the crystal grains is 400 nm or less; and the second conductors comprising a metal or an alloy selected from the group consisting of copper, copper alloy, aluminum, and aluminum alloy, and having higher electrical conductivity than the first conductors, wherein when viewed from a transverse cross-section of the twisted wire conductor, a proportion B1 occupied by the number of first conductors in the total number of first conductors and second conductors, which are positioned in an outermost layer of the twisted wire conductor, is higher than a proportion A occupied by the number of first conductors in the total number of first conductors and second conductors constituting the twisted wire conductor or the proportion B2 occupied by the number of first conductors in the total number of first conductors and second conductors, which are positioned within a region partitioned by a virtual circle that is concentric with a circumscribed circle of the twisted wire conductor and has a radius equal to a half of a radius of the circumscribed circle, is higher than the proportion A occupied by the number of first conductors in the total number of first conductors and second conductors constituting the twisted wire conductor. <EOS>