Köyliö () is a former municipality of Finland. It was merged to the municipality of Säkylä on 1 January 2016. It was located in the Satakunta region. The population of Köyliö was (30 June 2015) and covered a land area of . The population density was . The municipality was unilingually Finnish. It is said that the peasant Lalli murdered the English bishop Henry on the ice of Lake Köyliö in 1156 AD, during the first Swedish Crusade into Finland. A statue to Lalli was erected at Köyliö in 1989. Twinnings Before the 2016 consolidation, Köyliö was twinned with; Nora, Sweden (1944) Kõo, Estonia (1991) Fladungen, Germany (1996) References External links Municipality of Köyliö – Official website Municipalities of Satakunta Former municipalities of Finland Populated places established in 1870 Köyliö 1870 establishments in Finland