A stackable plastic booster seat apparatus with a body having a set of four corner cylindrical portions. A right foot having cylindrical portions engages two of the corner cylindrical portions and a left foot engages the other two corner cylindrical portions. The body includes a back with a lumbar support, a seat with a safety bump and a downward and rearward slope such that a child tends to sit properly in the apparatus away from the safety bump and against the lumbar support.