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Ontario

$39+ Cheap flights from Denver to Ontario (DEN - ONT)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 4/4. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — ONT
Feb 25 — Mar 41
Tue 2/25
Tue 3/4
1 adult, Economy
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The best prices from Denver Intl to Ontario are usually found in April or August, booked 83 days in advance, depart on a Tuesday or Saturday and return on a Saturday

Cheap flight deals from Denver to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Denver (DEN) to Ontario (ONT). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated February 20, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$59
(Frontier)

One-way from

$39
(Cheapflightsfares)

Popular in

February

Cheapest in

April

Average price

$180

Good round-trip deal

$85 or less

Good one-way deal

$44 or less
Provider with most accurate pricing for Denver Intl-Ontario flight deals.
Search Deals
Provider most trusted by Cheapflights users for Denver Intl-Ontario flights.
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From Denver Intl to Ontario
Search Deals
One-way flight from Denver Intl to Ontario
Search Deals
Highest demand for flights based on searches. 11% potential increase in price ($16 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($5 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in February 2025
Search Deals
Price to beat on a round-trip flight from Denver Intl to Ontario.
Search Deals
Price to beat on a one-way flight from Denver Intl to Ontario.
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Find flight deals from Denver to Ontario

Cheapest flights from Denver to Ontario
Explore the most affordable flight options available from Denver to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on February 20, 2025.

This Kiwi.com deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/1210:32 pmDEN - ONT
Nonstop2h 32mFrontier
Sun 3/1612:59 amONT - DEN
Nonstop2h 17mFrontier
Deal found 2/20$62
This Southwest deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/118:00 amDEN - ONT
Nonstop2h 20mSouthwest
Thu 4/243:55 pmONT - DEN
1 stop3h 50mSouthwest
Deal found 2/20$127
This Travelocity deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Travelocity is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/1010:37 pmDEN - ONT
Nonstop2h 32mMultiple Airlines
Mon 3/177:00 amONT - DEN
1 stop5h 54mMultiple Airlines
Deal found 2/20$142
This United Airlines deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/87:19 pmDEN - ONT
Nonstop2h 23mUnited Airlines
Sun 4/135:00 amONT - DEN
Nonstop2h 19mUnited Airlines
Deal found 2/20$158
This American Airlines deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/298:09 amDEN - ONT
1 stop4h 50mAmerican Airlines
Wed 4/304:35 pmONT - DEN
1 stop4h 13mAmerican Airlines
Deal found 2/20$199
This Delta deal was found by Cheapflights users on 2/20. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 3/68:25 amDEN - ONT
1 stop4h 59mDelta
Mon 3/106:00 amONT - DEN
1 stop6h 03mDelta
Deal found 2/20$216

Find flights from Denver to Ontario within your budget

Customize your flight search to find flights from Denver to Ontario that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 20, 2025.

Fly from

Denver

Fly to

Ontario

Route

Depart

Return

Price

DenverOntario

DEN - ONT

DENONT

Denver Intl

Wed 3/12

10:32 pm-12:04 am

Nonstop2h 32m

Ontario

Sun 3/16

12:59 am-4:16 am

Nonstop2h 17m

$62

DenverOntario

DEN - ONT

DENONT

Denver Intl

Fri 4/11

8:00 am-9:20 am

Nonstop2h 20m

Ontario

Thu 4/24

3:55 pm-8:45 pm

1 stop3h 50m

$127

DenverOntario

DEN - ONT

DENONT

Denver Intl

Mon 3/10

10:37 pm-12:09 am

Nonstop2h 32m

Ontario

Mon 3/17

7:00 am-1:54 pm

1 stop5h 54m

$142

DenverOntario

DEN - ONT

DENONT

Denver Intl

Tue 4/8

7:19 pm-8:42 pm

Nonstop2h 23m

Ontario

Sun 4/13

5:00 am-8:19 am

Nonstop2h 19m

$158

DenverOntario

DEN - ONT

DENONT

Denver Intl

Tue 4/29

8:09 am-11:59 am

1 stop4h 50m

Ontario

Wed 4/30

4:35 pm-9:48 pm

1 stop4h 13m

$199

DenverOntario

DEN - ONT

DENONT

Denver Intl

Thu 3/6

8:25 am-12:24 pm

1 stop4h 59m

Ontario

Mon 3/10

6:00 am-1:03 pm

1 stop6h 03m

$216

DenverOntario

DEN - ONT

DENONT

Denver Intl

Fri 4/4

10:37 pm-11:59 pm

Nonstop2h 22m

$39

DenverOntario

DEN - ONT

DENONT

Denver Intl

Wed 4/2

7:05 pm-10:35 pm

1 stop4h 30m

$74

DenverOntario

DEN - ONT

DENONT

Denver Intl

Tue 4/22

6:37 pm-11:58 pm

1 stop6h 21m

$77

DenverOntario

DEN - ONT

DENONT

Denver Intl

Sat 4/5

11:16 am-3:59 pm

1 stop5h 43m

$100

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/20

Showing 1-10 of 14 results
1
2

Compare providers for flights from Denver to Ontario

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Denver to Ontario in February.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust Score*3 stars
CheapflightsfaresPrice Accuracy3 starsTrust Score*2 stars
Kiwi.comPrice Accuracy3 starsTrust Score*2 stars
Justfly.comPrice Accuracy3 starsTrust Score*3 stars
CheapfaremartPrice Accuracy-Trust Score*3 stars
MytripPrice Accuracy3 starsTrust Score*3 stars
CheapOairPrice Accuracy1 starTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Denver-Ontario flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Denver-Ontario flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Denver-Ontario flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Denver-Ontario flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Denver-Ontario flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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 round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Travel insights for flights from Denver to Ontario

Get recent, data-driven insights about flights from Denver to Ontario including ideal travel times, pricing trends, and more.

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

Use this chart to determine the optimal time to book a round-trip flight from Denver to Ontario. Price data was last updated on February 14, 2025.

The price you pay for your flight from Denver to Ontario may vary depending on when you book. For the best chance of a lower fare, look to book 83 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 Denver to Ontario?

Currently, August is the cheapest month in which you can book a flight from Denver to Ontario (average of $246). Flying from Denver to Ontario in March is currently the most expensive (average of $315). 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?

Find hourly flight availability from Denver to Ontario. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated February 20, 2025.

One of the essential ways to save on airfare from Denver to Ontario is to remain as flexible as possible. Flights that are at noon tend to be the most expensive. A flight in the morning could potentially save you up to 39% on airfare.

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

Use this chart to determine the cheapest time to fly round-trip from Denver to Ontario. Price data was last updated on February 16, 2025.

Travelers seeking maximum savings on their Denver to Ontario flight should consider departing on Saturday at noon when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from Denver to Ontario

Explore weekly flight availability from Denver to Ontario. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated February 20, 2025.

The most flights from DEN to ONT are scheduled on a Thursday (11 on average). You will have fewer flight options on Friday, which is when the least amount of flights are scheduled (4 on average).

Rainfall in Ontario by month

Plan your trip to Ontario by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Ontario ranges from 0.1 - 3.4 inches per month. February is typically the wettest month, when rainfall can reach 3.4 in. June is typically the driest time to visit Ontario when rainfall is around 0.1 in.

Temperature in Ontario by month

Plan your trip to Ontario by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Ontario, use this chart to help with planning. For those seeking warmer temperatures, August is the ideal time of year to visit, when temperatures reach an average of 78.8 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 53.6 F).

Reviews of airlines servicing Ontario

Get insights into the airlines that provide service to Ontario. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Ontario. Reviews last updated February 20, 2025.
To help decide which airline to fly from Denver to Ontario, see what other customers have to say about Southwest, Alaska Airlines and Delta. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Boarding

8.2

Overall

8.1

Comfort

8.1

Food

7.1

Crew

8.7

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

Southwest
8.1
Very good
4,411 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Boarding

8.2

Overall

8.1

Comfort

8.1

Food

7.1

Crew

8.7

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

Alaska Airlines
8.0
Very good
9,697 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Boarding

8.2

Overall

8.1

Comfort

8.1

Food

7.1

Crew

8.7

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

Delta
8.0
Very good
8,219 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Boarding

8.2

Overall

8.1

Comfort

8.1

Food

7.1

Crew

8.7

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

Hawaiian Airlines
7.9
Good
2,317 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Boarding

8.2

Overall

8.1

Comfort

8.1

Food

7.1

Crew

8.7

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

United Airlines
7.4
Good
8,765 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Boarding

8.2

Overall

8.1

Comfort

8.1

Food

7.1

Crew

8.7

Reviews

1 / 20

8.0
Excellent

Christine,Aug 2024

DEN - LGB

No issues. I needed pre boarding and I was able to get it without issue

Related info for your journey

Find useful and relevant information for your journey from Denver to Ontario. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airports do I use to fly from Denver to Ontario?

    You will need to book a flight from Denver Intl to Ontario if you want to fly from Denver to Ontario. At least 3 different airlines have flights from Denver Intl (DEN) to Ontario (ONT) on a regular basis. There are 6 flights to Ontario from the Denver airport per day. If you manage to book one that is nonstop, then you can expect the flight time from DEN to ONT to be around 2h 15m.

  • How popular is this Denver to Ontario flight route?

    Flights from Denver Intl to Ontario have been viewed 92 times in the past calendar month.

  • What are the cheapest airlines flying from Denver to Ontario round-trip?

    According to our current data, Frontier ($59), Southwest ($127), and American Airlines ($199) offers the cheapest pricing from Denver to Ontario. Frontier is priced at 56% lower than the current average price of a flight leaving 3 months from now.

  • What are the cheapest airlines to fly from Denver to Ontario one-way?

    For one-way options, check prices for Frontier. According to our data, you can fly for as low as $39. Users have also found prices from $74 and $77 on Southwest and Hawaiian Airlines, respectively.

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

    Before booking your flight to Ontario from Denver, check out the most reliable airlines to get you to your destination on time: United Airlines (86%), Air Canada (81%), Frontier( 79%).

  • What are the cheapest flights from Denver to Ontario?

    The cheapest flight price from Denver to Ontario is $26. On average you can expect to pay $111. The most popular route, (Denver Intl - Ontario), can usually be booked for $43.

  • 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 vacation 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, August is the cheapest month in which you can book a flight from Denver to Ontario (average of $246). Flying from Denver to Ontario in March is currently the most expensive (average of $315). 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.

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Alternative routes for Denver to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
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Top 3 airlines flying from Denver to Ontario

Discover the top 3 airlines that operate flights from Denver to Ontario. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated February 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$47Average$120FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$141Average$307FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$178Average$255FlexibilityNo cancel feeOn-time63%
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