Merrillville ( /mɛrəlvɪl/) 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.
Merrillville is located at 41°29′08″N 87°20′07″W / 41.485669°N 87.335390°W / 41.485669; -87.335390.
According to the United States Census Bureau, the town has a total area of 33.3 square miles (86.3 km²), of which, 33.3 square miles (86.2 km²) of it is land and 0.04 square miles (0.1 km²) of it (0.09%) is water.