The present invention provides an automotive rotary electric machine that can suppress unnecessary disengagement of a protective cover by increasing supporting strength for the protective cover. The automotive rotary electric machine according to the present invention includes: a rectifier and a voltage regulator that are disposed outside a first axial end of a casing; and a resin protective cover that is formed so as to have a cup shape that is constituted by a bottom portion and a cylindrical peripheral wall portion, and that is mounted onto a casing so as to cover the rectifier and the voltage regulator. The protective cover is held by a circuit board of the rectifier by coupling by snap-fitting a plurality of projections that are disposed so as to protrude from an inner circumferential wall surface of the peripheral wall portion to a plurality of projection-engaging portions that are formed on an outer peripheral wall surface of the circuit board so as to be separated circumferentially.