Askainen is a former municipality in the Southwest Finland region of Finland. It was consolidated with the municipality of Lemu into Masku on January 1, 2009, and is therefore no longer an independent municipality.
Askainen is located in southwestern Finland, in the same region as the city of Turku. Before the 2009 consolidation, it formed a small rural municipality alongside its neighbour Lemu; both were merged into Masku, which now administers the area.