Onarga is a village located in Iroquois County, in the state of Illinois (IL), United States. Nestled in the East North Central division of the Midwest region, it covers an area of 1.3 square miles (3.0 km²) and sits at an elevation of 667 ft. With a population of approximately 1,438 residents, Onarga offers a peaceful, rural atmosphere.
The town's population is composed of about 52.29% males and 47.71% females, and it has a population density of 97.71 people per square mile (423.83/km²). Onarga lies at a latitude of 40.72 and a longitude of -88.01, operating in the UTC-6.
Locals reflect a blend of American ancestry, with roots primarily in United States (7%), followed by English (8.4%), German (18.8%), and Scotch-Irish (0%) heritage. The town is identified by the ZIP code 60955.