Pargas (Finnish: Parainen) is a town and municipality of Finland, in the Archipelago Sea, the biggest archipelago in the world by the number of islands, 50,000. The big limestone mine in Pargas is the base of the main industry and except for the central parts, the municipality is still mostly rural.

Pargas is located in Åboland in the province of Western Finland and is part of the Southwest Finland region. It was created as Väståboland on 1 January 2009 in Southwest Finland, when the municipalities of Pargas, Nagu, Korpo, Houtskär and Iniö were merged into a single municipality.

The municipality has a population of 14,814 (30 June 2025) and covers an area of 5,548.17 square kilometres (2,142.16 sq mi) of which 4,666.46 km² (1,801.73 sq mi) is water. The population density is 16.76 inhabitants per square kilometre (43.4/sq mi).

Pargas is a bilingual municipality with Finnish and Swedish as its official languages. The population consists of 41% Finnish speakers, 54% Swedish speakers, and 5% speakers of other languages.

Pargas has a large limestone industry, with the industry and Nordkalk as an important local employer, agriculture employs many in the rural regions of the municipality. Furthermore, the shipping industry is a relevant industry in the region. The municipality is suffering from high debt.

Archaeological excavations revealed that the vikings used to travel to the archipelago in the 9th century.

Karin Thomasdotter (1610–1697), who served as vogt in Pargas for over forty years, was one of the longest serving vogts, and also one of only two females to have the position in contemporary Finland.

Population in Pargas from 1749 to 1845 ("Women, Men, Children, & Nobles") as gathered by Sven Gabriel Elmgren.