Merrillville /mrlvl/ is a town in Ross Township, Lake County, Indiana, United States. The population was 35,246 at the 2010 census. Merrillville is located in the east-central portion of Lake County. The town is centered around the intersection of US 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 Highway 30) is known as 81st Avenue. State Road 53 (Broadway) and State Road 55 (Taft Street) traverse the town from north to south.