A vehicle-occupant protection system in a vehicle has a first sensor and a second sensor on a lateral side closer to a seat of an occupant. The first sensor is either forward of or lateral to the seat of the occupant in the front-rear direction of the vehicle. The second sensor is rearward of the first sensor. The system further includes a collision determination section, which concludes an occurrence of a collision when a signal of the first sensor exceeds a determination threshold value in a situation where a signal of the second sensor has not exceeded a determination threshold value. Upon concluding the occurrence of the collision, the collision determination section activates a movement restraint device to restrain the occupant from moving away from the seat.