A paint roller adapter enabling a large diameter paint roller cover to be used on a paint roller frame having a cage configured to receive smaller paint roller covers. The adapter is generally cylindrical in shape and comprises a cylindrical internal surface having a diameter sized to fit onto the cage of the roller frame and a substantially cylindrical external surface having a diameter sized to fit within the large paint roller cover. At least one gripping member projects outward, beyond the external surface of the adapter such that, in use, the gripping member(s) press against an internal surface of the large paint roller cover. The gripping members of the adapter serve to prevent the roller cover slipping about the external surface of the adapter. A pair of such adapters thereby enables a conventional paint roller frame to be used with large diameter roller covers.