Tonica is a village in LaSalle County, Illinois, United States. The population was 685 at the 2000 census. It is part of the Ottawa–Streator Micropolitan Statistical Area.
Tonica is mainly farmland, with a few businesses. It has its own grade school, Tonica Grade School (K-8), with approximately 194 students enrolled.
Tonica is located at 41°12′57″N 89°4′5″W / 41.21583°N 89.06806°W / 41.21583; -89.06806 (41.215902, -89.067981).