A seat assembly for a shopping cart includes a gate pivotally mounted to a rear portion of the shopping cart and a seat member made from a plastic material. The seat member is mounted to the gate of the shopping cart via a pivot mechanism to extend in a position to support a child within the shopping cart. The seat member includes a generally curved concave portion having an apex adjacent the gate and a generally straight portion on a side of the seat member opposite the apex of the generally curved concave portion.