Trimble County is a county located in the U.S. state of Kentucky. As of the 2010 census, the population was 8,809. Its county seat is Bedford. The county was founded in 1837 and is named for Robert Trimble. Trimble is a prohibition or dry county.Trimble County is part of the Louisville/Jefferson County, KY - IN Metropolitan Statistical Area.GeographyAccording to the U.S. Census Bureau, the county has a total area of, of which is land and (2.9%) is water. It is the fifth-smallest county in Kentucky by land area and fourth-smallest by total area. The county's western border with Indiana is formed by the Ohio River.Adjacent countiesJefferson County, Indiana (northwest)Carroll County (east)Henry County (southeast)Oldham County (southwest)Clark County, Indiana (west)