Cheap flights from Denver to Ontario
from 203 US$
From 83 USD — compare hundreds of airlines
The cheapest month is usually 2026-10 · 203 US$
See prices for my dates →Live fares from 100+ sites — free, with no hidden fees.
About this route
Compare flights from Denver to Ontario, a about 1,289 km route (around 2h 7m 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 United Airlines, 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 Denver to Ontario?
It's usually 2026-10, from 203 USD. Use the price calendar to compare other dates.
How long is the flight from Denver to Ontario?
A nonstop flight takes about 2h 7m and covers around 1,289 km. Connecting itineraries take longer.
Are there direct flights from Denver to Ontario?
Yes, this route has nonstop flights. Filter by "nonstop" to see them.
Which airlines fly from Denver to Ontario?
United Airlines, Southwest Airlines operate this route, among others. Compare them all in the results.
When should I book Denver–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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Denver → Ontario · Live fares from 100+ sites — free, with no hidden fees.