Rymättylä is a former municipality in the Southwest Finland region of Finland. It was consolidated with the town of Naantali on January 1, 2009, together with Merimasku and Velkua. Since that date it has formed part of Naantali rather than functioning as an independent municipality.
Before the consolidation, Rymättylä bordered the municipalities of Korpo, Merimasku, Naantali, Nagu, Pargas, Turku and Velkua. Its location in the archipelago of Southwest Finland placed it among a group of coastal and island municipalities, several of which were also merged into Naantali in the same reform.