How to find the cheapest flight from
Ontario (ONT) to Illinois
How far in advance should I book a flight from Ontario to Illinois?
To save up to 10% on this flight, we recommend booking at least 37 days prior to travel. The price may fluctuate and will likely increase closer to your departure date. Users on Cheapflights have found tickets from Ontario to Illinois from $177 1-2 weeks out and tickets from $177 for flights departing within the next 72 hours.
One-way flights to Illinois from Ontario
The cheapest one-way flights from Ontario to Illinois
6:49 am - 3:20 pm
6:20 pm - 7:30 am
Related info for your journey
Useful info, stats and facts about Ontario to Illinois flights.
Arrival points for flights from Ontario to Illinois
Destination information for Illinois
Things to know before you go. Useful info for your trip from Ontario to Illinois