Merrillville is a town in Ross Township, Lake County, Indiana. The population was 35,246 at the 2010 census. Merrillville is located in the east-central portion of Lake County, in the Chicago metropolitan area. On January 1, 2015, Merrillville became the most populated town in Indiana, as Fishers in Hamilton County was converted from a town to a city.GeographyMerrillville is located at.According to the 2010 census, Merrillville has a total area of 33.26sqmi, of which 33.22sqmi (or 99.88%) is land and 0.04sqmi (or 0.12%) is water.The town is centered on the intersection of U.S. Route 30 and Interstate 65.The Lincoln Highway runs through Merrillville. The original alignment of Lincoln Highway is known as 73rd Avenue (also called Old Lincoln Highway) in Merrillville, while the current Lincoln Highway (US 30) is known as 81st Avenue. State Road 53 (Broadway) and State Road 55 (Taft Street) traverse the town from north to south.The asymmetric shape of Merrillville results in numerous boundaries with other municipalities. Merrillville is bordered by Gary and unincorporated Calumet Township, Lake County, to the north; Hobart to the northeast; Union Township, Porter County, to the east; Winfield and Crown Point to the south; Schererville to the west; and Griffith to the northwest.