Lewisville is a city in Lafayette County, Arkansas, United States. The population was 1,280 at the 2010 census. It is the county seat of Lafa…Lewisville is a city in Lafayette County, Arkansas, United States. The population was 1,280 at the 2010 census. It is the county seat of Lafayette County. Lewisville is located in northern Lafayette County. U.S. Route 82 passes through the south side of the city, leading east 23 miles to Magnolia and west 30 miles to Texarkana. Arkansas Highway 29 passes through the center of Lewisville, leading north 23 miles to Hope and south 19 miles to Bradley.