An airbag device includes: an airbag that is provided on a vehicle front side of a front passenger seat provided in a cabin, inflates as a result of a gas being supplied to the inside of the airbag, and deploys on the vehicle front side of an occupant seated in the front passenger seat; an airbag housing that is provided on the vehicle front side of the front passenger seat and in which is housed the airbag before inflating; and an airbag door that covers the airbag housing from the cabin side and becomes displaced toward the cabin side when the airbag inflates, whereby the airbag door opens the cabin side of the airbag housing. Movement of the airbag in the vehicle width direction after complete deployment is limited by at least part of the airbag door.