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Cheap flights from Denver to Ontario from £26

DEN — ONT
29 Nov — 6 Dec1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Denver to Ontario

Enter your travel dates to find the best prices.

Cheapest flights from Denver to Ontario

Tue 24/1105:45 -
1 stop4h 05m
Tue 24/1112:45 -
Nonstop2h 15m
Deal found 28/10£106
Mon 23/1112:45 -
Nonstop2h 20m
Thu 26/1111:45 -
Nonstop2h 10m
Deal found 29/10£108
Thu 3/1208:50 -
Nonstop2h 20m
Sun 6/1214:45 -
Nonstop2h 15m
Deal found 27/10£123
Mon 21/1218:28 -
1 stop6h 31m
Wed 6/107:10 -
1 stop5h 57m
Deal found 28/10£133
Thu 24/1215:10 -
2 stops6h 30m
Thu 31/1212:50 -
1 stop4h 10m
Deal found 27/10£136
Tue 22/1219:35 -
Nonstop2h 25m
Tue 5/113:42 -
Nonstop2h 19m
Deal found 28/10£139
Thu 26/1112:55 -
1 stop6h 35m
Fri 4/1213:11 -
1 stop6h 21m
Deal found 28/10£148
Sat 5/1212:49 -
1 stop4h 39m
Mon 7/1213:11 -
1 stop6h 21m
Deal found 27/10£148
Fri 4/1208:45 -
1 stop5h 30m
Sun 6/1205:00 -
2 stops5h 10m
Deal found 27/10£151
Fri 4/1208:10 -
1 stop5h 07m
Sun 6/1206:00 -
1 stop4h 59m
Deal found 27/10£155

Find flight deals from Denver to Ontario

Round-trip from

£106

One-way from

£26

Popular in

June

Cheapest in

May

Average price

£163

Good one-way deal

£119 or less
Southwest
  • Southwest
  • 24/11-24/11
  • 1 total stop
  • 6h 20m total
  • Denver to Ontario
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Frontier
  • Frontier
  • 2/2-31/12
  • Nonstop
  • 2h 25m total
  • Denver to Ontario
Search Deals
Highest demand for flights based on searches. 7% potential increase in price (£11 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease (£4 potential savings vs. average return price).
Search Deals
Average for round-trip flights in October 2026
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Price to beat on a one-way flight from Denver Intl to Ontario.
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Cheapflights Fare Finder

 
Use the filters below to find and compare flights from Denver to Ontario that are best for you.

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Depart

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Price

Cheapest return flight
Fastest return journey

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Tue 17/11

11:15-12:33

Nonstop2h 18m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£59

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Mon 4/1

14:20-18:30

1 stop5h 10m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£67

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Wed 20/1

12:29-16:27

1 stop4h 58m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£89

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Sat 12/12

19:45-21:11

Nonstop2h 26m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£89

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Fri 4/12

19:45-21:11

Nonstop2h 26m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£97

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Tue 24/11

05:45-08:50

1 stop4h 05m

Ontario

Tue 24/11

12:45-16:00

Nonstop2h 15m

£106

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Mon 23/11

12:45-14:05

Nonstop2h 20m

Ontario

Thu 26/11

11:45-14:55

Nonstop2h 10m

£108

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Mon 16/11

06:00-12:29

1 stop7h 29m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£109

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Fri 4/12

18:11-23:57

1 stop6h 46m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£120

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Thu 3/12

08:50-10:10

Nonstop2h 20m

Ontario

Sun 6/12

14:45-18:00

Nonstop2h 15m

£123

Flights are sorted by cheapest return flights first.

Deals found on 25/10

Showing 1-10 of 22 resultsSorted by cheapest first
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Best time to book a flight from Denver to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Denver with our price prediction graph.
Estimated return price

Cheapflights Insights

Everything you need to know about your flight from Denver to Ontario

How far ahead should I book a flight from Denver to Ontario?

Booking 48 days in advance of your planned departure date is, on average, the best time to get cheap flights from Denver to Ontario. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

What is the cheapest month to book a flight from Denver to Ontario?

Currently, May is the cheapest month in which you can book a flight from Denver to Ontario (average of £132). Flying from Denver to Ontario in June is currently the most expensive (average of £217). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from DEN to ONT?

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Denver to Ontario as you normally would.

How much does it cost for a return flight from Denver to Ontario?

Airfare is typical for this route at the moment.

Denver to Ontario flights typically cost between £101 and £250 in November.
The cheapest return price found within the last 5 days was £106 on Southwest (24 Nov–24 Nov).

Related info for your journey

  • How popular is this Denver to Ontario flight route?

    Flights from Denver Intl to Ontario have been viewed 1 times in the past calendar month.

  • How long is the flight from Denver to Ontario?

    There are many flights that can get you from Denver to Ontario in 4h 05m. Fly via Southwest or Delta to get the fastest option. Airlines will cover a distance of 817 mi. When browsing for deals, the options you’ll see will be for both direct flights and flights with stops.

  • What are the most reliable airlines from Denver to Ontario?

    No one likes to see their flight delayed. When booking a flight from Denver to Ontario consider choosing Frontier (83%), Volaris (83%) or United Airlines (69%) as they are the most reliable in getting you off to your destination on time.

  • Can I find deals for flights from Denver to Ontario that include hotel bookings?

    Yes. In addition to deals on Denver to Ontario flights, Cheapflights offers holiday packages that include both flights and hotel.

  • How can I find direct flights from Denver to Ontario?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Denver to Ontario.

  • Can I find deals for business class flights from Denver to Ontario?

    Yes. Cheapflights offers flight deals from Denver to Ontario by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Denver to Ontario?

    Currently, May is the cheapest month in which you can book a flight from Denver to Ontario (average of £132). Flying from Denver to Ontario in June is currently the most expensive (average of £217). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Alternative routes for Denver to Ontario

Denver to Las Vegas flights
Denver to Santa Ana flights
Denver to San Francisco flights
Denver to San Diego flights

Fly with Cheapflights

How does Cheapflights help users find flights from Denver to Ontario?

Deals for Denver to Ontario flights are sourced from 900+ travel sites when you use Cheapflights. When all flight results come back, Cheapflights lets you sort and filter flights using different criteria to choose better, like price, airport, cabin class, and plenty of other options.

Why should you use Cheapflights to find cheap flight tickets from Denver to Ontario?

Cheapflights simply makes it quick and affordable to book flights from Denver to Ontario by bringing together all flight options from hundreds of airlines and agencies online — and put it in one place for you to choose from. Plus, Cheapflights is 100% free to use for all.

Can Cheapflights find flights from Denver to Ontario with no change fees?

Yes, we can. To see specific flights from Denver to Ontario with no change fees, users can toggle flexible booking options after using the search form above to find flights.

Can Cheapflights notify me if prices for flights from Denver to Ontario become cheaper?

Yes, Cheapflights has a feature called Price Alert, which notifies users when flight prices change. Track prices for your flight to Ontario from Denver today and book when prices fit your budget.

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