Vehicle airbag device and vehicle occupant restraint device

A vehicle airbag device comprises an airbag that receives gas supplied from an inflator and that is adapted to be inflated and deployed in front of an upper body and above thighs of an occupant seated in a vehicle seat. The airbag includes, in the event that the gas has been supplied inside the airbag and the airbag inflates and deploys, an inflation section having an endless annular shape as viewed along a vehicle width direction, and a hollow section formed in a central portion of the inflation section. The hollow section is in communication with an exterior of the airbag, and air at the exterior flows into the hollow section during inflation and deployment.