To provide an occupant detection system and occupant detection method making it possible to concentrate system components inside or around equipment which an occupant operates.

An occupant detection system (100) in accordance with the present invention is an occupant detection system that detects an occupant who operates equipment loaded on a vehicle, and includes: an electrode unit (120) that is electrically connected to an operating unit via an impedance which is produced by the occupant when the occupant manipulates the operating unit of the equipment; a signal generation unit (130) that generates a signal and feeds the signal to the electrode unit; and a signal discrimination unit (140) that discriminates the signal which the signal generation unit has fed to the electrode unit.