Tonica is a village in LaSalle County, Illinois, United States. The population was 685 at the 2000 census. Tonica is mainly farmland, with a few businesses. It has its own grade school, Tonica Grade School, with approximately 194 students enrolled. Tonica apartments for rent comparison page shows most up to date rent information on Tonica apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.