A golf club head having an adjustable hosel assembly and a plug assembly that can reversibly secure the hosel assembly in a chosen configuration within the club head is disclosed herein. In particular, the hosel assembly includes a shaft sleeve that is trapped within a hosel opening with a screw that extends through an interior flange. The plug assembly includes a wedge-shaped flange that is inserted into an opening in the body and fits between the interior flange and the head of the screw to temporarily immobilize the shaft sleeve. The plug assembly preferably completely fills the opening in the body so as to preserve a smooth outer mold line of the club head and allow graphics or decorations to extend across the exterior surface without disruption.