Abstract: An occupancy alarm system for warning a driver of vehicle occupancy includes an electronics module that is configured to couple to a vehicle, and which is operationally couplable to an electronic control unit (ECU) and an electrical circuit of the vehicle. The electronics module comprises a module transceiver and a plurality of sensors, which is configured to determine an occupancy status of the vehicle. A fob device that is retained by a driver who exits the vehicle comprises a fob receiver, which is GPS enabled, a fob transceiver, and a speaker. CPU programming code that is positioned on a CPU of the ECU enables the ECU to selectively actuate the module transceiver, based on occupancy status of the vehicle and a position of the driver relative to the vehicle, to communicate an alert signal to the fob device via the fob transceiver to alert the driver to the occupancy status.