An airbag attachment structure includes: a door portion whose one end portion is opened when an airbag is deployed; an attachment portion to which an airbag case for storing the airbag is attached, and which has an opening at which the door portion is opened and brought into an opened state when the airbag is deployed; a hinge portion configured to turnably hold the door portion; a guide portion protruding from the attachment portion to narrow a deployment passage between the airbag and the door portion, and configured to guide deployment of the airbag; and a flap connected to the guide portion, interposed between the airbag and the hinge portion, and configured to turn together with the door portion when being biased by the airbag during deployment of the airbag, and the guide portion has higher rigidity than the flap.