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$47+ Cheap flights from Colorado to Ontario (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 5/20. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — ONT
May 5 — May 121
Mon 5/5
Mon 5/12
1 adult, Economy
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Cheap flight deals from Colorado to Ontario

Keep the following information in mind while searching for Colorado to Ontario flight deals. Data was last updated April 30, 2025.

Most accurate provider

Mytrip
3 stars

Most trusted provider

Mytrip
3 stars

Round-trip from

$94
(Cheapflightsfares)

One-way from

$47
(Cheapflightsfares)

Popular in

December

Cheapest in

January

Average price

$178

Good round-trip deal

$131 or less

Good one-way deal

$96 or less
Provider with most accurate pricing for Denver Intl-Los Angeles flight deals.
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Provider most trusted by Cheapflights users for Denver Intl-Los Angeles flights.
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From Colorado to Ontario
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One-way flight from Colorado to Ontario
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Highest demand for flights based on searches. 4% potential increase in price ($8 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($3 potential savings vs. average RT price).
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Average for round-trip flights in April 2025
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Price to beat on a round-trip flight from Colorado to Ontario.
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Price to beat on a one-way flight from Colorado to Ontario.
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Find flight deals from Colorado to Ontario

Cheapest flights from Colorado to Ontario
Explore the most affordable flight options available from Colorado to Ontario. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 30, 2025.

This Cheapflightsfares deal was found by Cheapflights users on 4/29. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/39:20 amDEN - ONT
Nonstop2h 23mFrontier
Tue 6/36:42 pmONT - DEN
Nonstop2h 25mFrontier
Deal found 4/29$94
This Expedia deal was found by Cheapflights users on 4/29. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/37:05 pmDEN - ONT
1 stop5h 52mMultiple Airlines
Fri 6/65:21 pmONT - DEN
Nonstop2h 21mMultiple Airlines
Deal found 4/29$161
This United Airlines deal was found by Cheapflights users on 4/29. 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 5/207:30 pmDEN - ONT
Nonstop2h 23mUnited Airlines
Wed 5/211:20 pmONT - DEN
Nonstop2h 19mUnited Airlines
Deal found 4/29$197
This Alaska Airlines deal was found by Cheapflights users on 4/29. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/247:05 pmDEN - ONT
1 stop5h 52mAlaska Airlines
Sat 5/314:45 pmONT - DEN
1 stop6h 20mAlaska Airlines
Deal found 4/29$207
This Delta deal was found by Cheapflights users on 4/29. 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.
Sat 5/246:25 pmDEN - ONT
1 stop4h 51mDelta
Sun 5/254:57 pmONT - DEN
1 stop4h 33mDelta
Deal found 4/29$217
This Delta deal was found by Cheapflights users on 4/28. 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.
Tue 8/198:00 amCOS - ONT
1 stop5h 23mDelta
Sun 8/319:55 amONT - COS
1 stop6h 18mDelta
Deal found 4/28$244
This United Airlines deal was found by Cheapflights users on 4/29. 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.
Wed 6/1812:50 pmCOS - ONT
1 stop5h 35mUnited Airlines
Tue 7/296:10 amONT - COS
2 stops7h 28mUnited Airlines
Deal found 4/29$276
This United Airlines deal was found by Cheapflights users on 4/28. 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.
Thu 8/283:24 pmMTJ - ONT
1 stop6h 09mUnited Airlines
Mon 9/15:10 amONT - MTJ
1 stop6h 37mUnited Airlines
Deal found 4/28$287
This Delta deal was found by Cheapflights users on 4/28. 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.
Fri 5/236:05 amGJT - ONT
1 stop4h 06mDelta
Tue 5/274:57 pmONT - GJT
1 stop4h 36mDelta
Deal found 4/28$289
This United Airlines deal was found by Cheapflights users on 4/29. 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.
Wed 6/41:45 pmGJT - ONT
2 stops10h 00mUnited Airlines
Sun 6/85:10 amONT - GJT
1 stop6h 36mUnited Airlines
Deal found 4/29$294
This Southwest deal was found by Cheapflights users on 4/29. 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.
Wed 6/184:45 pmCOS - ONT
2 stops6h 20mSouthwest
Tue 7/292:10 pmONT - COS
2 stops7h 30mSouthwest
Deal found 4/29$294
This American Airlines deal was found by Cheapflights users on 4/28. 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.
Sat 5/174:39 pmGJT - ONT
1 stop8h 04mAmerican Airlines
Wed 5/286:15 amONT - GJT
1 stop8h 54mAmerican Airlines
Deal found 4/28$299

Cheapflights Fare Finder

Customize your flight search to find flights from Colorado 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 April 30, 2025.
Use the filters below to find and compare flights from Colorado to Ontario that are best for you.

Fly from

Colorado

Fly to

Ontario

Route

Depart

Return

Price

DenverOntario

DEN - ONT

DENONT

Denver Intl

Tue 6/3

9:20 am-10:43 am

Nonstop2h 23m

Ontario

Tue 6/3

6:42 pm-10:07 pm

Nonstop2h 25m

$94

DenverOntario

DEN - ONT

DENONT

Denver Intl

Tue 6/3

7:05 pm-11:57 pm

1 stop5h 52m

Ontario

Fri 6/6

5:21 pm-8:42 pm

Nonstop2h 21m

$161

DenverOntario

DEN - ONT

DENONT

Denver Intl

Tue 5/20

7:30 pm-8:53 pm

Nonstop2h 23m

Ontario

Wed 5/21

1:20 pm-4:39 pm

Nonstop2h 19m

$197

DenverOntario

DEN - ONT

DENONT

Denver Intl

Sat 5/24

7:05 pm-11:57 pm

1 stop5h 52m

Ontario

Sat 5/31

4:45 pm-12:05 am

1 stop6h 20m

$207

DenverOntario

DEN - ONT

DENONT

Denver Intl

Sat 5/24

6:25 pm-10:16 pm

1 stop4h 51m

Ontario

Sun 5/25

4:57 pm-10:30 pm

1 stop4h 33m

$217

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Tue 8/19

8:00 am-12:23 pm

1 stop5h 23m

Ontario

Sat 8/30

9:55 am-5:13 pm

1 stop6h 18m

$244

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Wed 6/18

12:50 pm-5:25 pm

1 stop5h 35m

Ontario

Tue 7/29

6:10 am-2:38 pm

2 stops7h 28m

$276

MontroseOntario

MTJ - ONT

MTJONT

Montrose County

Thu 8/28

3:24 pm-8:33 pm

1 stop6h 09m

Ontario

Mon 9/1

5:10 am-12:47 pm

1 stop6h 37m

$287

Grand JunctionOntario

GJT - ONT

GJTONT

Grand Junction Regnl

Fri 5/23

6:05 am-9:11 am

1 stop4h 06m

Ontario

Tue 5/27

4:57 pm-10:33 pm

1 stop4h 36m

$289

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Wed 6/18

4:45 pm-10:05 pm

2 stops6h 20m

Ontario

Tue 7/29

2:10 pm-10:40 pm

2 stops7h 30m

$294

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/29

Showing 1-10 of 37 results
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Best time to book a flight from Colorado to Ontario

Have a flexible travel schedule? Discover the best time to fly to Ontario from Colorado 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.

Cheapflights Insights

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

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

Currently, August is the cheapest month in which you can book a flight from Colorado to Ontario (average of $246). Flying from Colorado to Ontario in March is currently the most expensive (average of $328). 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 CO to ONT?

Find hourly flight availability from Colorado 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 April 30, 2025.

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

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 April 30, 2025.
Get a feel of what it's like to fly with Alaska Airlines, Southwest and Delta from Colorado to Ontario by reading reviews from past customers. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
9,968 reviews

Entertainment

7.1

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
9,968 reviews
Alaska Airlines
8.0
Very good
9,968 reviews

Entertainment

7.1

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,295 reviews
Alaska Airlines
8.0
Very good
9,968 reviews

Entertainment

7.1

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,936 reviews
Alaska Airlines
8.0
Very good
9,968 reviews

Entertainment

7.1

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Hawaiian Airlines
7.9
Good
2,406 reviews
Alaska Airlines
8.0
Very good
9,968 reviews

Entertainment

7.1

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,696 reviews
Alaska Airlines
8.0
Very good
9,968 reviews

Entertainment

7.1

Boarding

8.2

Overall

8.0

Crew

8.5

Food

7.1

Comfort

7.9

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Related info for your journey

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

  • What airport do you fly into for flights to Ontario from Colorado?

    If you book a flight to Ontario from Colorado, you will be flying to Ontario, which is the city’s only airport. Ontario (ONT) is located 3.1 mi from the center of Ontario.

  • How popular is this Colorado to Ontario flight route?

    The Colorado to Ontario flight path was viewed by 78 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

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

    The cheapest airlines for a one-way flight from Colorado to Ontario are Frontier ($47), Alaska Airlines ($99), and American Airlines ($100).

  • What are the most popular routes from Colorado to Ontario?

    While some choose either Colorado Springs - Ontario or Grand Junction Regnl - Ontario, Denver Intl - Ontario is the most popular route from Colorado to Ontario.

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

    No one likes to see their flight delayed. When booking a flight from Colorado to Ontario consider choosing SkyWest Airlines (100%), Air Canada (86%) or United Airlines (81%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from Colorado to Ontario?

    While on average a flight from Colorado to Ontario is generally $148, our data shows the cheapest flight currently is $46. When looking at the most popular route, (Denver Intl - Ontario), you can expect to pay $94 for that flight.

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

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

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

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

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

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

    Currently, August is the cheapest month in which you can book a flight from Colorado to Ontario (average of $246). Flying from Colorado to Ontario in March is currently the most expensive (average of $328). 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

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Alternative routes for Colorado to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
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Top 5 airlines flying from Colorado to Ontario

Discover the top 5 airlines that operate flights from Colorado 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 April 30, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$55Average$127FlexibilityNo cancel feeOn-time62%
SouthwestCheapest$117Average$320FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$137Average$343FlexibilityNo cancel feeOn-time69%
DeltaCheapest$218Average$322FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$278Average$361FlexibilityNo cancel feeOn-time71%

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