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Cheap flights from Ontario to Denver from C$ 215

ONT — DEN
17 Oct — 24 Oct1
1 adult
1 adult, Economy, 0 bags

Cheap flight deals from Ontario to Denver

Enter your travel dates to find the best prices.

Cheapest flights from Ontario to Denver

Wed 30/91:50 p.m. -
Nonstop2h 15m
Sat 3/108:55 a.m. -
Nonstop2h 25m
Deal found 16/9C$ 400
Wed 11/1110:05 a.m. -
Nonstop2h 15m
Wed 18/111:15 p.m. -
Nonstop2h 25m
Deal found 14/9C$ 434
Mon 12/105:40 a.m. -
Nonstop2h 15m
Tue 13/104:40 p.m. -
Nonstop2h 20m
Deal found 16/9C$ 443
Tue 13/103:10 p.m. -
1 stop5h 50m
Tue 20/104:40 p.m. -
Nonstop2h 20m
Deal found 15/9C$ 445
Wed 23/92:30 p.m. -
1 stop18h 37m
Sat 26/910:50 p.m. -
1 stop9h 14m
Deal found 12/9C$ 449
Thu 22/104:25 p.m. -
1 stop5h 45m
Sat 24/105:45 a.m. -
2 stops6h 25m
Deal found 12/9C$ 455
Wed 28/101:35 p.m. -
1 stop4h 59m
Tue 3/117:15 a.m. -
1 stop6h 21m
Deal found 16/9C$ 459

Find flight deals from Ontario to Denver

Round-trip from

C$ 400

One-way from

C$ 215

Popular in

June

Cheapest in

February

Average price

C$ 364

Good one-way deal

C$ 393 or less
Southwest
  • Southwest
  • 30/9-3/10
  • Nonstop
  • 4h 40m total
  • Ontario to Denver
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Alaska Airlines
  • Alaska Airlines
  • 28/10-31/12
  • 1 total stop
  • 7h 06m total
  • Ontario to Denver
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Highest demand for flights based on searches. 20% potential increase in price (C$ 112 potential increase over avg. RT price).
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Cheapest flight prices on average. 3% potential price decrease (C$ 18 potential savings vs. average RT price).
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Average for round-trip flights in September 2026
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Price to beat on a one-way flight from Ontario to Denver Intl.
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Cheapflights Fare Finder

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

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

OntarioDenver

ONT Ontario - DEN Denver Intl

ONTDEN

Ontario

Wed 28/10

6:02 a.m.-2:08 p.m.

1 stop7h 06m

Denver Intl

Wed 31/12

12:00 a.m.-11:00 p.m.

Nonstop0h 00m

C$ 215

OntarioDenver

ONT Ontario - DEN Denver Intl

ONTDEN

Ontario

Wed 7/10

1:24 p.m.-4:45 p.m.

Nonstop2h 21m

Denver Intl

Wed 31/12

12:00 a.m.-11:00 p.m.

Nonstop0h 00m

C$ 272

OntarioDenver

ONT Ontario - DEN Denver Intl

ONTDEN

Ontario

Wed 28/10

5:00 a.m.-8:17 a.m.

Nonstop2h 17m

Denver Intl

Wed 31/12

12:00 a.m.-11:00 p.m.

Nonstop0h 00m

C$ 272

OntarioDenver

ONT Ontario - DEN Denver Intl

ONTDEN

Ontario

Sat 14/11

1:29 p.m.-4:45 p.m.

Nonstop2h 16m

Denver Intl

Wed 31/12

12:00 a.m.-11:00 p.m.

Nonstop0h 00m

C$ 272

OntarioDenver

ONT Ontario - DEN Denver Intl

ONTDEN

Ontario

Tue 13/10

5:00 a.m.-8:21 a.m.

Nonstop2h 21m

Denver Intl

Wed 31/12

12:00 a.m.-11:00 p.m.

Nonstop0h 00m

C$ 272

OntarioDenver

ONT Ontario - DEN Denver Intl

ONTDEN

Ontario

Thu 22/10

5:03 p.m.-10:40 p.m.

1 stop4h 37m

Denver Intl

Wed 31/12

12:00 a.m.-11:00 p.m.

Nonstop0h 00m

C$ 273
Quickest round-trip

OntarioDenver

ONT Ontario - DEN Denver Intl

ONTDEN

Ontario

Sun 11/10

5:40 p.m.-8:50 p.m.

Nonstop2h 10m

Denver Intl

Wed 31/12

12:00 a.m.-11:00 p.m.

Nonstop0h 00m

C$ 287

OntarioDenver

ONT Ontario - DEN Denver Intl

ONTDEN

Ontario

Thu 29/10

6:00 a.m.-11:56 a.m.

1 stop4h 56m

Denver Intl

Wed 31/12

12:00 a.m.-11:00 p.m.

Nonstop0h 00m

C$ 301

OntarioDenver

ONT Ontario - DEN Denver Intl

ONTDEN

Ontario

Sat 10/10

1:35 p.m.-7:34 p.m.

1 stop4h 59m

Denver Intl

Wed 31/12

12:00 a.m.-11:00 p.m.

Nonstop0h 00m

C$ 301

OntarioDenver

ONT Ontario - DEN Denver Intl

ONTDEN

Ontario

Thu 1/10

6:15 a.m.-11:27 a.m.

1 stop4h 12m

Denver Intl

Wed 31/12

12:00 a.m.-11:00 p.m.

Nonstop0h 00m

C$ 312

Flights are sorted by cheapest round-trip flights first.

Deals found on 16/9

Showing 1-10 of 23 resultsSorted by cheapest first
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Best time to book a flight from Ontario to Denver

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

Cheapflights Insights

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

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

The price you pay for your flight from Ontario to Denver may vary depending on when you book. For the best chance of a lower fare, look to book 66 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

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

Currently, February is the cheapest month in which you can book a flight from Ontario to Denver (average of C$ 229). Flying from Ontario to Denver in June is currently the most expensive (average of C$ 450). 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 ONT to DEN?

It’s typically best to fly out from Ontario to Denver in the afternoon. Doing so could potentially save you 45% on the flight price compared to flying in the morning, which is usually more expensive.

How much does it cost to fly round-trip from Ontario to Denver?

Airfare is typical for this route at the moment.

Ontario to Denver flights typically cost between C$ 237 and C$ 487 in September.
The cheapest round-trip price found within the last 5 days was C$ 400 on Southwest (30 Sep-3 Oct).

Related info for your journey

  • How popular is this Ontario to Denver flight route?

    Within the past month, 5 users have taken a look at flights from Ontario to Denver Intl.

  • How long is the flight from Ontario to Denver?

    There are many flights that can get you from Ontario to Denver in 4h 59m. Fly via Southwest or Delta to get the fastest option. Airlines will cover a distance of 1315 km. This flight may include one or multiple stops.

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

    Consider Frontier (93%), Volaris (93%) or Air Canada (84%) when booking your flight. These represent the most reliable airlines when flying from Ontario to Denver.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Ontario to Denver 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 Ontario to Denver?

    Currently, February is the cheapest month in which you can book a flight from Ontario to Denver (average of C$ 229). Flying from Ontario to Denver in June is currently the most expensive (average of C$ 450). 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

Travelling to a place near Denver?

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Black Hawk

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Alternative routes for Ontario to Denver

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When you search for this flight from Ontario to Denver, Cheapflights searches on 900+ travel sites to save you time finding great flight deals online. Additionally, we offer filter features so you can choose a preferred cabin class or airline, see different price ranges, and much more so you can book the flight for you.

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

Cheapflights taps into our reliable network of hundreds of airlines and travel agencies to find the best deals for flights from Ontario to Denver for you. Better yet — we are completely free to use.

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

Cheapflights does show flights with no change fees to all users. To see these options for flights from Ontario to Denver, users can toggle the no change fees filter when performing a flight search.

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Not ready to book yet? You can track prices for flights from Ontario to Denver on Cheapflights with our Price Alert feature and get notified when better prices are available.

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