VEHICLE OCCUPANT RESTRAINT DEVICE

A vehicle occupant restraint device (10) includes a side airbag (36). The side airbag (36) includes a main chamber (38) provided to a side portion of a seat back (16) of a vehicle seat (12) and configured to be inflated and deployed to the inward side in the vehicle-width direction of an occupant (P), and a sub-chamber (40) configured to be inflated and deployed to the inward side in the vehicle-width direction from a lower portion of the main chamber (38). When the vehicle seat (12) assumes a front-side position at which a front end face (16A) of the side portion of the seat back (16) is positioned on a forward side than a front face (22A) of a console box (20) in side view, the sub-chamber (40) is contactable with the front face (22A) of the console box (20) from the forward side.