Find flights
Deals
When to book
FAQs

Cheap flights from Denver to Ontario from £107

DEN — ONT
16 Oct — 23 Oct1
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

Sat 24/1008:55 -
Nonstop2h 25m
Sat 24/1012:45 -
Nonstop2h 10m
Deal found 16/9£235
Thu 22/1008:30 -
1 stop4h 55m
Sat 24/1005:30 -
2 stops5h 50m
Deal found 11/9£242
Sat 10/1010:45 -
1 stop6h 38m
Tue 13/1017:03 -
1 stop4h 37m
Deal found 15/9£244
Tue 27/1014:45 -
2 stops6h 05m
Sat 31/1005:40 -
2 stops7h 30m
Deal found 11/9£246
Tue 13/1016:30 -
1 stop5h 55m
Tue 20/1006:10 -
2 stops6h 05m
Deal found 14/9£248
Sat 7/1112:57 -
1 stop4h 26m
Mon 9/1117:04 -
1 stop5h 05m
Deal found 16/9£267
Tue 27/1012:31 -
2 stops29h 34m
Wed 4/1106:00 -
1 stop6h 58m
Deal found 14/9£271
Mon 26/1005:25 -
1 stop4h 30m
Tue 27/1009:45 -
1 stop6h 11m
Deal found 16/9£274
Fri 23/1020:50 -
1 stop4h 05m
Sat 31/1008:25 -
2 stops7h 40m
Deal found 13/9£277
Thu 3/1216:02 -
1 stop5h 36m
Mon 7/1205:00 -
Nonstop2h 17m
Deal found 14/9£280

Find flight deals from Denver to Ontario

Round-trip from

£223

One-way from

£107

Popular in

June

Cheapest in

May

Average price

£141

Good one-way deal

£118 or less
Southwest
  • Southwest
  • 14/10-19/10
  • Nonstop
  • 4h 40m total
  • Denver to Ontario
Search Deals
United Airlines
  • United Airlines
  • 14/11-31/12
  • Nonstop
  • 2h 26m total
  • Denver to Ontario
Search Deals
Highest demand for flights based on searches. 9% potential increase in price (£13 potential increase over avg. return price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease (£4 potential savings vs. average return price).
Search Deals
Average for round-trip flights in September 2026
Search Deals
Price to beat on a one-way flight from Denver Intl to Ontario.
Search Deals

Cheapflights Fare Finder

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

Fly from

Fly to

Route

Depart

Return

Price

Cheapest return flight

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Sat 14/11

19:25-20:51

Nonstop2h 26m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£107

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Wed 14/10

07:07-13:16

1 stop7h 09m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£122

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Mon 26/10

08:20-12:36

1 stop5h 16m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£145

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Mon 12/10

05:25-08:55

1 stop4h 30m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£145

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Fri 13/11

15:10-19:55

2 stops5h 45m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£150

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Mon 16/11

18:10-23:49

1 stop6h 39m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£160

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Sat 10/10

12:25-18:00

2 stops6h 35m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£164
Fastest return journey

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Fri 25/12

19:35-21:00

Nonstop2h 25m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£168

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Mon 16/11

19:25-20:51

Nonstop2h 26m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£168

DenverOntario

DEN Denver Intl - ONT Ontario

DENONT

Denver Intl

Thu 12/11

19:25-20:51

Nonstop2h 26m

Ontario

Wed 31/12

00:00-01:00

Nonstop0h 00m

£168

Flights are sorted by cheapest return flights first.

Deals found on 15/9

Showing 1-10 of 23 resultsSorted by cheapest first
1
2
3

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 £131). Flying from Denver to Ontario in June is currently the most expensive (average of £215). 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 above average for this route at the moment.

Denver to Ontario flights typically cost between £86 and £213 in October.
The cheapest return price found within the last 5 days was £235 on Southwest (24 Oct–24 Oct).

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 2h 30m. Fly via Delta, Southwest, or Alaska Airlines 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 (81%), Volaris (81%) or Air Canada (72%) 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 £131). Flying from Denver to Ontario in June is currently the most expensive (average of £215). 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 San Francisco flights
Denver to Santa Ana 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.

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.