Cheap flights from Chicago to Ontario
from 85 US$
From 171 USD — compare hundreds of airlines
The cheapest month is usually 2026-09 · 85 US$
See prices for my dates →Live fares from 100+ sites — free, with no hidden fees.
About this route
Compare flights from Chicago to Ontario, a about 2,755 km route (around 3h 57m nonstop). We gather live prices from hundreds of airlines and agencies so you can find the cheapest and book on the official site, with no hidden fees. Direct flights are available. Airlines such as Southwest Airlines operate this route.
When to buy and when to fly
Prices by date
Fares found by date — cheapest days in green.
How to get the best price
Airlines on this route
FAQ
What's the cheapest month to fly Chicago to Ontario?
It's usually 2026-09, from 85 USD. Use the price calendar to compare other dates.
How long is the flight from Chicago to Ontario?
A nonstop flight takes about 3h 57m and covers around 2,755 km. Connecting itineraries take longer.
Are there direct flights from Chicago to Ontario?
Yes, this route has nonstop flights. Filter by "nonstop" to see them.
Which airlines fly from Chicago to Ontario?
Southwest Airlines operate this route, among others. Compare them all in the results.
When should I book Chicago–Ontario flights?
As a rule of thumb, booking 3–8 weeks ahead and avoiding weekends and holidays tends to give the best prices. Use the calendar to spot the cheapest dates.
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Chicago → Ontario · Live fares from 100+ sites — free, with no hidden fees.