Nyland and Tavastehus County (Swedish: Nylands och Tavastehus län, Finnish: Uudenmaan ja Hämeen lääni) was a county of the Swedish Empire in Finland from 1634 to 1809. In 1775 whole northern part of the county (later Central Finland region) was transferred to the new Vasa County. Also a part of historical Satakunta was added to the Nyland and Tavastehus County from the Åbo and Björneborg County, while Upper Hollola was transferred to the new Kymmenegård County.