A vehicle body rear part structure for a vehicle includes a side frame, a subframe disposed below the side frame, and a vehicle body frame member disposed on a middle side in the vehicle body front-rear direction with respect to the subframe. The vehicle body frame member includes: a vertical frame offset outwardly in the vehicle width direction with respect to the subframe; and a lateral frame extending inwardly in the vehicle width direction from the vertical frame. A connecting portion is provided on the subframe. The connecting portion includes: an inclined portion extending while being inclined outwardly in the vehicle width direction, to face the vertical frame; and a widening portion widening inwardly in the vehicle width direction up to a position where the connecting portion linearly extends in the vehicle body front-rear direction from the inclined portion, to face the lateral frame.