An interlock circuit for a utility vehicle park brake includes a relay connected to neutral switch on a transmission. The relay is actuated by electric current to move a contact to a closed position if the neutral switch is out of neutral. A throttle pedal switch connected to the relay moves a contact to a closed position if the throttle pedal is depressed. A park brake switch connected to the throttle pedal switch moves a contact to a closed position if the park brake is engaged. Closing all of the contacts grounds an ignition circuit connected to the interlock circuit, which may be a magneto ignition circuit.