Piikkiö is a former municipality in the Southwest Finland region of Finland. It was consolidated with the town of Kaarina on 1 January 2009, after which it ceased to function as an independent municipality.
It is located in the south-western part of the country, within the broader Southwest Finland region, an area whose coastal and inland settlements include a number of communities that have been merged into larger administrative units in recent decades.
Since the 2009 merger, Piikkiö has formed part of Kaarina rather than existing as a separate municipal entity. Its status as a former municipality is the defining administrative fact about the place.