Abstract: A vehicle occupancy warning system includes a vehicle that has a door and a back seat. The back seat may have a child seated therein. The door is selectively positioned between an open position and a closed position. A sensing unit is coupled to the vehicle and the sensing unit is aligned with the door. The sensing unit senses when the door is positioned in the open position and the closed position. An alarm unit is positioned within the vehicle and the alarm unit is in electrical communication with the sensing unit. The alarm unit emits an audible alarm when the sensing unit senses that the door is in the open position. In this way the alarm unit reminds a driver to check for the child in the back seat thereby inhibiting the child from being left unattended in the vehicle.