Abstract: A slipover headrest pillow assembly includes an invaginable open bottom cover having a pocket along the front side thereof, with such pocket initially being exposed for insertion of a foam pillow. The cover is then invaginated to enclose the pillow and to form a support compartment between such pillow pocket and the top and back walls of the cover, such support compartment receiving the top of the seat back when the cover has been slipped over the same to support such pillow assembly in a headrest position. The pocket may include a flap initially hanging freely downwardly to permit the pillow to be inserted in the pocket during assembly and then extending up and over the seat back within the support compartment after installation to enclose the pillow within the pocket.