Vehmaa (Finnish pronunciation: [ˈʋehmɑː]; Swedish: Vemo) is a municipality of Finland. It is located in the province of Western Finland and is part of the Southwest Finland region. The municipality has a population of 2,268 (31 August 2024) and covers an area of 202.09 square kilometres (78.03 sq mi) of which 13.32 km2 (5.14 sq mi) is water. The population density is 12.01 inhabitants per square kilometre (31.1/sq mi).
The municipality is unilingually Finnish.
Vehmaa is known of their red Granite Balmoral red, as well as being the birthplace of Albin Stenroos who won the gold medal in the marathon at the 1924 Olympics. According to Traficom, Vehmaa is the fifth most motorized municipality in Finland with 628 cars per 1000 inhabitants.