Cheap flights from Denver to Ontario

One-way fares from $121 · DEN → ONT · prices found by travellers in the last 48 hours

Compare all dates Ontario → Denver
Cheapest fare
$121

Frontier Airlines · Sat, Nov 14

Cheapest month
November

from $121

Direct flights
Yes

Southwest Airlines

Flight time
2h 25m

1,290 km

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Cheapest month to fly from Denver to Ontario

Lowest one-way fare per person in each month. Choose a month to see every date.

  1. November 2026 Cheapest $121

Cheapest dates in November 2026

The lowest fares we've seen for each day, cheapest first.

Frontier Airlines
Depart09:28 Sat, Nov 14DEN → ONT 3h 15m · 1 stop
$121one way, per person
View deal
Southwest Airlines
Depart08:35 Sat, Nov 28DEN → ONT 2h 25m · Direct
$144one way, per person
View deal
Frontier Airlines
Depart07:30 Thu, Nov 12DEN → ONT 3h 13m · 1 stop
$171one way, per person
View deal
Frontier Airlines
Depart10:47 Fri, Nov 13DEN → ONT 5h 25m · 1 stop
$171one way, per person
View deal
See every date in November 2026 →

Plan the rest of your trip to Ontario

Where to stay, what to do and getting around, from our travel partners.

Where to stay

Hotels in OntarioCompare places to stay on Booking.com Find hotels →

Things to do

Things to do in OntarioTours, attractions and day trips on Klook Explore →

Getting around

Airport transfer in OntarioPre-book a driver to meet you at arrivals, with Kiwitaxi Book a transfer → Car hire in OntarioCompare rental cars from major brands on EconomyBookings Compare cars →

About flights from Denver to Ontario

Denver (DEN) and Ontario (ONT) are about 1,290 km apart. Direct flights take around 2h 25m, and recent direct fares were with Southwest Airlines. Over the next few months, one-way fares start from $121, and November 2026 is currently the cheapest month to fly.

These prices come from searches travellers made in the last 48 hours, so they move quickly. If you see a good fare, it's worth booking soon. FlightsExp is free to use: you book directly with our travel partner.

Frequently asked questions

How much is a flight from Denver to Ontario?

The cheapest one-way fare we've seen recently is $121 with Frontier Airlines, departing Saturday, November 14, 2026.

What is the cheapest month to fly from Denver to Ontario?

November 2026 currently has the lowest fares, from $121 one way.

Are there direct flights from Denver to Ontario?

Yes. Recent direct fares were with Southwest Airlines.

How long is the flight from Denver to Ontario?

A direct flight takes about 2h 25m. Denver and Ontario are around 1,290 km apart.

Which airlines fly from Denver to Ontario?

Recent fares on this route were with Frontier Airlines and Southwest Airlines.

More cheap flights from Denver

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