A vehicular occupant protection apparatus (10) is equipped with a seatbelt (12) including a shoulder belt portion (12A) fitted to a occupant (P) from a shoulder part thereof to a lumbar part thereof, a pretensioner mechanism (24) that is actuated to remove slack in the seatbelt (12), a force limiter mechanism (26) for limiting a restraint load applied to the occupant by the seatbelt (12), an air belt device (44) that supplies an air belt (45) with gas to inflate/deploy the air belt (45) between the occupant (P) and an instrument panel, and a occupant protection ECU (55) that actuates the air belt device (44) such that the air belt (45) starts being supplied with gas upon or after start of actuation of the force limiter mechanism (26) following actuation of the pretensioner mechanism (24) in the event of a head-on collision of a vehicle.