The present invention is skimmer plug for winterizing a pool. The skimmer plug inserts and grips into the fluid opening, where there is fluid passage from the pool to the skimmer housing and filter assembly. In this manner, the surface of the skimmer plug when installed is slightly raised from the factory skimmer faceplate or skimmer opening by only the thickness of the skimmer plug's outer plate. The fasteners which secure the factory skimmer faceplate and the skimmer housing to the pool sidewall still remain accessible for adjustment by the pool owner or pool service personnel while the skimmer plug is securely in place.