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Cheap flights from Ontario to Denver from $28

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Ontario to Denver departing on 6/2. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Ontario to Denver

Cheap round-trip flights

These are some of the best round-trip flight deals from Ontario to Denver that have been recently found on momondo from popular airlines, departing in the coming months.

Cheap one-way flights

Flying one-way? These are some of the best deals recently discovered on momondo for flights from Ontario to Denver.

Cheap last minute flights

Planning a quick getaway from Ontario to Denver? These are the last-minute flight deals available now.

Cheap direct flights

If you prefer a non-stop journey, check out our latest direct flight deals to Denver, so you can enjoy a seamless trip without layovers.

Cheap bus & train deals from Ontario to Denver

Find recent round-trip train or bus tickets from Ontario to Denver.

All round-trip flight deals from Ontario to Denver

The cheapest plane tickets from Ontario to Denver found on KAYAK recently.
3:17 pm - 6:41 pmONT-DEN
2h 24mnonstop
10:37 pm - 11:59 pmDEN-ONT
2h 22mnonstop
$53Frontier
Find Deal
Wed, Apr 9 - Wed, Apr 9
6:45 am - 10:04 amONT-DEN
2h 19mnonstop
10:27 pm - 11:59 pmDEN-ONT
2h 32mnonstop
$58Frontier
Find Deal
Sat, Feb 8 - Tue, Feb 25
5:45 am - 9:00 amONT-DEN
2h 15mnonstop
8:55 am - 10:25 amDEN-ONT
2h 30mnonstop
$157Southwest
Find Deal
Wed, Feb 26 - Sat, Mar 1
4:30 pm - 7:40 pmONT-DEN
2h 10mnonstop
8:50 pm - 10:20 pmDEN-ONT
2h 30mnonstop
$177Southwest
Find Deal
Sat, Feb 15 - Wed, Feb 19
5:05 am - 8:24 amONT-DEN
2h 19mnonstop
7:25 pm - 8:52 pmDEN-ONT
2h 27mnonstop
$217United Airlines
Find Deal
Tue, Feb 18 - Tue, Feb 25
6:10 am - 12:09 pmONT-DEN
4h 59m1 stop
11:24 am - 3:29 pmDEN-ONT
5h 05m1 stop
$222American Airlines
Find Deal
Tue, Feb 11 - Wed, Feb 12
5:05 am - 8:24 amONT-DEN
2h 19mnonstop
1:30 pm - 8:40 pmDEN-ONT
8h 10m1 stop
$227United Airlines
Find Deal
Wed, Feb 26 - Wed, Feb 26
6:13 am - 11:42 amONT-DEN
4h 29m1 stop
7:46 am - 12:07 pmDEN-ONT
5h 21m1 stop
$228American Airlines
Find Deal
Sun, Feb 16 - Wed, Feb 19
6:00 am - 11:37 amONT-DEN
4h 37m1 stop
8:25 am - 12:24 pmDEN-ONT
4h 59m1 stop
$237Delta
Find Deal
Sun, Feb 16 - Thu, Feb 20
6:00 am - 1:03 pmONT-DEN
6h 03m1 stop
6:10 pm - 11:56 pmDEN-ONT
6h 46m1 stop
$248Delta
Find Deal
Wed, Mar 26 - Wed, Mar 26
12:59 am - 4:18 amONT-DEN
2h 19mnonstop
$28Frontier
Find Deal
Mon, Jun 2
12:59 am - 4:16 amONT-DEN
2h 17mnonstop
$29Frontier
Find Deal
Tue, Mar 4
12:10 pm - 3:32 pmONT-DEN
2h 22mnonstop
$34Frontier
Find Deal
Sat, Apr 26
5:05 am - 8:15 amONT-DEN
2h 10mnonstop
$79Southwest
Find Deal
Sat, Feb 22
3:30 pm - 9:45 pmONT-DEN
5h 15m1 stop
$89United Airlines
Find Deal
Wed, Feb 19
5:15 am - 8:25 amONT-DEN
2h 10mnonstop
$99Southwest
Find Deal
Sun, Feb 23
10:05 am - 3:27 pmONT-DEN
4h 22m1 stop
$100American Airlines
Find Deal
Wed, Feb 19
5:05 am - 8:24 amONT-DEN
2h 19mnonstop
$109United Airlines
Find Deal
Tue, Feb 18
6:00 am - 11:37 amONT-DEN
4h 37m1 stop
$129Delta
Find Deal
Sun, Feb 16
4:05 pm - 12:17 amONT-DEN
7h 12m1 stop
$132Delta
Find Deal
Sat, Mar 8
6:45 am - 10:04 amONT-DEN
2h 19mnonstop
10:15 pm - 11:47 pmDEN-ONT
2h 32mnonstop
$58Frontier
Find Deal
Sat, Jan 25 - Wed, Jan 29
6:45 am - 10:04 amONT-DEN
2h 19mnonstop
10:15 pm - 11:47 pmDEN-ONT
2h 32mnonstop
$59Frontier
Find Deal
Sat, Jan 25 - Tue, Feb 4
6:45 am - 10:04 amONT-DEN
2h 19mnonstop
8:07 am - 9:40 amDEN-ONT
2h 33mnonstop
$68Frontier
Find Deal
Sat, Jan 25 - Fri, Jan 31
6:00 am - 3:49 pmONT-DEN
8h 49m1 stop
7:00 am - 10:13 pmDEN-ONT
16h 13m2 stops
$510Alaska Airlines
Find Deal
Sat, Jan 25 - Sun, Jan 26
10:47 am - 2:21 pmONT-DEN
26h 34m2 stops
1:34 pm - 6:04 pmDEN-ONT
5h 30m1 stop
$528United Airlines
Find Deal
Wed, Jan 22 - Tue, Jan 28
6:39 pm - 11:07 amONT-DEN
15h 28m2 stops
10:42 pm - 7:11 amDEN-ONT
9h 29m1 stop
Fri, Jan 24 - Sun, Jan 26
6:15 am - 8:26 amONT-DEN
25h 11m2 stops
6:00 am - 9:51 amDEN-ONT
4h 51m1 stop
$548United Airlines
Find Deal
Sat, Jan 25 - Mon, Jan 27
11:33 am - 1:07 pmONT-DEN
24h 34m2 stops
4:45 pm - 10:38 amDEN-ONT
18h 53m1 stop
$575Alaska Airlines
Find Deal
Thu, Jan 23 - Sat, Feb 1
11:14 am - 10:36 pmONT-DEN
10h 22m2 stops
10:15 pm - 11:47 pmDEN-ONT
2h 32mnonstop
Tue, Jan 21 - Sat, Jan 25
1:21 pm - 7:21 pmONT-DEN
5h 00m1 stop
12:30 pm - 4:28 pmDEN-ONT
4h 58m1 stop
$859Delta
Find Deal
Wed, Jan 22 - Fri, Jan 24
3:17 pm - 6:41 pmONT-DEN
2h 24mnonstop
10:37 pm - 11:59 pmDEN-ONT
2h 22mnonstop
$53Frontier
Find Deal
Wed, Apr 9 - Wed, Apr 9
12:59 am - 4:18 amONT-DEN
2h 19mnonstop
10:38 pm - 11:59 pmDEN-ONT
2h 21mnonstop
$57Frontier
Find Deal
Mon, Jul 14 - Tue, Jul 22
7:45 am - 11:10 amONT-DEN
2h 25mnonstop
10:27 pm - 11:59 pmDEN-ONT
2h 32mnonstop
$58Frontier
Find Deal
Tue, Feb 11 - Tue, Feb 25
12:59 am - 4:16 amONT-DEN
2h 17mnonstop
10:27 pm - 11:59 pmDEN-ONT
2h 32mnonstop
$59Frontier
Find Deal
Mon, Feb 17 - Tue, Feb 25
4:30 pm - 7:40 pmONT-DEN
2h 10mnonstop
9:35 am - 11:05 amDEN-ONT
2h 30mnonstop
$157Southwest
Find Deal
Tue, Feb 18 - Tue, Feb 25
4:30 pm - 7:40 pmONT-DEN
2h 10mnonstop
8:50 pm - 10:20 pmDEN-ONT
2h 30mnonstop
$177Southwest
Find Deal
Sat, Feb 15 - Wed, Feb 19
5:45 am - 9:00 amONT-DEN
2h 15mnonstop
10:25 pm - 11:55 pmDEN-ONT
2h 30mnonstop
$197Southwest
Find Deal
Wed, Feb 26 - Thu, Feb 27
5:05 am - 8:24 amONT-DEN
2h 19mnonstop
7:30 pm - 8:57 pmDEN-ONT
2h 27mnonstop
$237United Airlines
Find Deal
Wed, Mar 5 - Tue, Mar 11
5:05 am - 8:24 amONT-DEN
2h 19mnonstop
7:30 pm - 8:57 pmDEN-ONT
2h 27mnonstop
$257United Airlines
Find Deal
Wed, Mar 26 - Wed, Mar 26
5:05 am - 8:24 amONT-DEN
2h 19mnonstop
7:25 pm - 8:52 pmDEN-ONT
2h 27mnonstop
$275United Airlines
Find Deal
Sat, Mar 1 - Sun, Mar 2

Frontier flights from Ontario to Denver

Our best Frontier deals on Ontario to Denver flight tickets
Frontier
Apr 9
ONT3:17 pmOntario
2h 24m
DEN6:41 pmDenver Intl
Apr 9
DEN10:37 pmDenver Intl
2h 22m
ONT11:59 pmOntario
Frontier
Feb 8
ONT6:45 amOntario
2h 19m
DEN10:04 amDenver Intl
Feb 25
DEN10:27 pmDenver Intl
2h 32m
ONT11:59 pmOntario
Frontier
Feb 17
ONT12:59 amOntario
2h 17m
DEN4:16 amDenver Intl
Feb 25
DEN10:27 pmDenver Intl
2h 32m
ONT11:59 pmOntario

Southwest flights from Ontario to Denver

Our best Southwest deals on Ontario to Denver flight tickets
Southwest
Feb 26
ONT5:45 amOntario
2h 15m
DEN9:00 amDenver Intl
Mar 1
DEN8:55 amDenver Intl
2h 30m
ONT10:25 amOntario
Southwest
Feb 15
ONT4:30 pmOntario
2h 10m
DEN7:40 pmDenver Intl
Feb 19
DEN8:50 pmDenver Intl
2h 30m
ONT10:20 pmOntario
Southwest
Feb 26
ONT5:45 amOntario
2h 15m
DEN9:00 amDenver Intl
Feb 27
DEN10:25 pmDenver Intl
2h 30m
ONT11:55 pmOntario

See travel insights to Denver from

How to get the cheapest flight ticket from Ontario to Denver

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Denver?

The cheapest month to fly to Denver from Ontario is in January. Flight prices, which tend to average around $128, are often lower during this time because this is during the off-season. If you don’t want to visit Denver in January, then you should wait until September to fly from Ontario, when ticket prices are also cheap, with an average price of $128.

What is the cheapest day to depart on your flight to Denver?

The cheapest day to depart on your flight to Denver is on a Saturday when prices can be found for as low as $172. This is often the case because there is less demand to fly during this day of the week. The most expensive day to fly to Denver is Sunday, with ticket prices averaging around $238.

What is the cheapest time of day to depart on your flight to Denver?

The cheapest time of day to fly to Denver is in the afternoon when flights can be purchased for as low as $183. Flights at noon are often more expensive with an average ticket price of $263.

What is the cheapest Ontario to Denver Intl flight route?

Fly from Ontario to Denver Intl for the best Ontario - Denver Intl flight prices

How far in advance should I book a flight to Denver?

You are more likely to see cheaper flights to Denver from Ontario when booking 4 weeks ahead of your departure date. In general, you can expect to find flights to Denver for around $149 when searching 4 weeks out.However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Denver from Ontario for as low as $108 on momondo.

What cabin class options are available on Ontario to Denver Intl flights?

There are 4 cabin classes available to choose from on Ontario to Denver Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

How have Ontario to Denver flight prices changed over time?

As of January 2025, prices for Ontario to Denver flights are approximately 10% cheaper when compared to flights at the same time last year.

When to book flights from Ontario to Denver

Are you open to changing your travel dates? Check out the ideal times to fly from Ontario to Denver according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Ontario to Denver (ONT to DEN) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Ontario to Denver

Best Price Found

$28

Fastest flight time

2h 10m

Direct flights

Every day

Airports in Denver

1 airport
The best one-way flight to Denver from Ontario in the past 72 hours is $28. The best round-trip flight deal from Ontario to Denver found on momondo in the last 72 hours is $53.
The fastest flight from Ontario to Denver takes 2h 10m
Direct flights go from Ontario to Denver every day.
There is 1 airport near Denver: Denver Intl (DEN)

  • How far is Ontario to Denver Intl by plane?

    The straight-line distance from Ontario to Denver Intl is 800.5 mi. A reasonable flight in good conditions will take 2h 10m.

  • When did momondo last update prices for flights from Ontario Airport to Denver Intl Airport?

    Prices for flights from Ontario Airport to Denver Intl Airport were last updated today.

  • How many operators does momondo search for flights from Ontario Airport to Denver Intl Airport?

  • How old do you have to be to fly from Ontario Airport to Denver Intl Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Ontario Airport to Denver Intl Airport.

  • What documentation or ID do you need to fly to Denver Intl Airport?

    The travel and health documents required for your trip to Denver Intl Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Denver Intl Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

  • What is the most popular plane model from Ontario to Denver?

  • What is the most popular airline from Ontario to Denver?


Best airlines flying from Ontario to Denver

Compare and see reviews for airlines that fly from Ontario to Denver with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $52Free CancellationRating
6.0
3,441 reviews
Search Frontier flights
United AirlinesPriceFrom $148Free CancellationRating
7.4
8,982 reviews
Search United Airlines flights
DeltaPriceFrom $159Free CancellationRating
8.0
8,521 reviews
Search Delta flights
American AirlinesPriceFrom $177Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
SouthwestPriceFrom $178Free CancellationRating
8.1
4,659 reviews
Search Southwest flights
  • Southwest Flights From Ontario to Denver

    Southwest flies from Ontario to Denver around 23 times per week, with 4,659 momondo users rating the airline 8.1/10. The cheapest Southwest deal from Ontario to Denver in the last 72 hours was $178 (round-trip), much lower than the average airfare cost of $258 for Southwest flights on this route.

  • United Airlines Flights From Ontario to Denver

    Another popular option for Ontario to Denver flights is United Airlines (7.4/10, 8,982 ratings). United Airlines flies from Ontario to Denver around 13 times per week, with deals starting from $148 round-trip and rising to an average price of around $293.


Traveling to a place near Denver?

Book flights to Denver if you plan to visit one of these locations
Estes Park
Breckenridge
Aurora
Fort Collins
Black Hawk
Lakewood
Keystone
Longmont
Boulder
Cripple Creek
Westminster
Greeley
Manitou Springs
Thornton
Sterling
Silverthorne
Frisco
Golden
Wheat Ridge
Winter Park

Why use momondo?

Why should I use momondo to find a flight deal from Ontario to Denver?

Finding the right flight to Denver from Ontario is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Denver quick and easy, saving you time and money.

Can I find flights from Ontario to Denver with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for Ontario to Denver flights to just show those with flexible booking policies.

How can momondo help me find flights from Ontario to Denver?

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Ontario to Denver.

I’m not ready to book a flight from Ontario to Denver right now. Can momondo alert me if prices change?

If you are simply researching potential flights to Denver, momondo offers a useful price alert feature which will track prices for flights to Denver from Ontario and alert you when they change.


An easier way to manage your Denver trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

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