The Pokémon League of Sinnoh is the location of the region's Elite Four, who may only be challenged after defeating all eight Sinnoh Gym Leaders. It is located on an island north of Route 223 and west of Route 224, and it is the only place in Sinnoh that requires considerable amounts of Surfing to reach.

Like in Kanto and Hoenn, reaching the Pokémon League requires first passing through Sinnoh's Victory Road (and a large waterfall) to the south of the League building. The Sinnoh League is located in a castle reminiscent of a Gothic cathedral, having a rose window and two towers at the very front of the building, characteristic of Gothic architecture.