HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Ontario

$42+ 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 2/21. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — ONT
Jan 26 — Feb 21
Sun 1/26
Sun 2/2
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Colorado to Ontario with Cheapflights

1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”
2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.
3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Colorado to Ontario

Discover tips and strategies to find the most affordable flight options for your journey from Colorado (USCO) 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 January 21, 2025.

Round-trip from

$77
(Kiwi.com)

One-way from

$44
(Mytrip)

Good round-trip deal

$80 or less

Good one-way deal

$55 or less
From Colorado to Ontario
Search Deals
One-way flight from Colorado to Ontario
Search Deals
Price to beat on a round-trip flight from Colorado to Ontario.
Search Deals
Price to beat on a one-way flight from Colorado to Ontario.
Search Deals

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 January 21, 2025.

This Frontier deal was found by Cheapflights users on 1/21. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 1/2910:15 pmDEN - ONT
Nonstop2h 32mFrontier
Sun 2/28:11 pmONT - DEN
Nonstop2h 22mFrontier
Deal found 1/21$78
This Frontier deal was found by Cheapflights users on 1/21. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 2/1412:09 pmEGE - ONT
1 stop7h 49mFrontier
Sat 2/1512:59 amONT - EGE
1 stop12h 08mFrontier
Deal found 1/21$121
This Southwest deal was found by Cheapflights users on 1/20. 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.
Thu 2/1310:25 pmDEN - ONT
Nonstop2h 30mSouthwest
Tue 2/181:35 pmONT - DEN
Nonstop2h 10mSouthwest
Deal found 1/20$197
This American Airlines deal was found by Cheapflights users on 1/21. 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 2/182:26 pmDEN - ONT
1 stop5h 00mAmerican Airlines
Tue 2/2510:05 amONT - DEN
1 stop4h 22mAmerican Airlines
Deal found 1/21$208
This Delta deal was found by Cheapflights users on 1/20. 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.
Tue 2/186:05 pmDEN - ONT
1 stop6h 46mDelta
Fri 2/284:05 pmONT - DEN
1 stop6h 37mDelta
Deal found 1/20$217
This Orbitz deal was found by Cheapflights users on 1/21. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 2/207:00 amDEN - ONT
2 stops10h 59mMultiple Airlines
Thu 2/279:35 pmONT - DEN
1 stop5h 21mMultiple Airlines
Deal found 1/21$226
This United Airlines deal was found by Cheapflights users on 1/21. 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.
Fri 2/217:25 pmDEN - ONT
Nonstop2h 27mUnited Airlines
Sat 2/225:05 amONT - DEN
Nonstop2h 19mUnited Airlines
Deal found 1/21$237
This Alaska Airlines deal was found by Cheapflights users on 1/21. 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.
Fri 2/74:45 pmDEN - ONT
1 stop6h 54mAlaska Airlines
Tue 2/116:00 amONT - DEN
1 stop15h 36mAlaska Airlines
Deal found 1/21$256
This Delta deal was found by Cheapflights users on 1/21. 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 2/228:20 amCOS - ONT
1 stop5h 04mDelta
Mon 2/241:21 pmONT - COS
1 stop4h 29mDelta
Deal found 1/21$287
This Delta deal was found by Cheapflights users on 1/21. 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 2/131:25 pmGJT - ONT
1 stop4h 03mDelta
Sun 2/166:00 amONT - GJT
1 stop5h 48mDelta
Deal found 1/21$289
This United Airlines deal was found by Cheapflights users on 1/21. 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 2/137:00 amGJT - ONT
2 stops8h 29mUnited Airlines
Sun 2/165:05 amONT - GJT
1 stop4h 49mUnited Airlines
Deal found 1/21$320
This Southwest deal was found by Cheapflights users on 1/21. 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.
Thu 2/134:30 pmMTJ - ONT
1 stop8h 25mSouthwest
Sun 2/165:15 amONT - MTJ
1 stop4h 50mSouthwest
Deal found 1/21$327

Find flights from Colorado to Ontario within your budget

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 January 21, 2025.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

DenverOntario

DEN - ONT

DENONT

Denver Intl

Thu 2/20

7:58 am-9:31 am

Nonstop2h 33m

Ontario

Sun 2/23

12:59 am-4:16 am

Nonstop2h 17m

$78

VailOntario

EGE - ONT

EGEONT

Vail Eagle County

Fri 2/14

12:09 pm-6:58 pm

1 stop7h 49m

Ontario

Sat 2/15

12:59 am-2:07 pm

1 stop12h 08m

$121

DenverOntario

DEN - ONT

DENONT

Denver Intl

Wed 2/19

8:50 pm-10:20 pm

Nonstop2h 30m

Ontario

Wed 2/26

5:45 am-9:00 am

Nonstop2h 15m

$157

DenverOntario

DEN - ONT

DENONT

Denver Intl

Thu 2/20

11:15 am-12:42 pm

Nonstop2h 27m

Ontario

Sat 2/22

1:44 pm-5:03 pm

Nonstop2h 19m

$177

DenverOntario

DEN - ONT

DENONT

Denver Intl

Tue 2/18

2:26 pm-6:26 pm

1 stop5h 00m

Ontario

Tue 2/25

10:05 am-3:27 pm

1 stop4h 22m

$208

DenverOntario

DEN - ONT

DENONT

Denver Intl

Thu 2/20

7:00 am-4:59 pm

2 stops10h 59m

Ontario

Wed 2/26

12:59 am-4:16 am

Nonstop2h 17m

$211

DenverOntario

DEN - ONT

DENONT

Denver Intl

Tue 2/18

6:05 pm-11:51 pm

1 stop6h 46m

Ontario

Fri 2/28

4:05 pm-11:42 pm

1 stop6h 37m

$217

DenverOntario

DEN - ONT

DENONT

Denver Intl

Fri 2/7

4:45 pm-10:39 pm

1 stop6h 54m

Ontario

Tue 2/11

6:00 am-10:36 pm

1 stop15h 36m

$256

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Sat 2/22

8:20 am-12:24 pm

1 stop5h 04m

Ontario

Mon 2/24

1:21 pm-6:50 pm

1 stop4h 29m

$287

Grand JunctionOntario

GJT - ONT

GJTONT

Grand Junction Regnl

Thu 2/13

1:25 pm-4:28 pm

1 stop4h 03m

Ontario

Sun 2/16

6:00 am-12:48 pm

1 stop5h 48m

$289

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/21

Showing 1-10 of 34 results
1
2
3
4

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.

Travel insights for flights from Colorado to Ontario

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

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 $310). 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 January 21, 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.

Weekly flight availability from Colorado to Ontario

Explore weekly flight availability from Colorado 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 January 21, 2025.

The most flights from USCO to ONT are scheduled on a Monday (15 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (2 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 January 21, 2025.
Get a feel of what it's like to fly with Frontier, United Airlines 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.
Southwest
8.1
Very good
4,662 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Entertainment

7.7

Overall

8.1

Food

7.2

Reviews

1 / 10

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

Southwest
8.1
Very good
4,662 reviews
Southwest
8.1
Very good
4,662 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Entertainment

7.7

Overall

8.1

Food

7.2

Reviews

1 / 10

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

Alaska Airlines
8.0
Very good
9,706 reviews
Southwest
8.1
Very good
4,662 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Entertainment

7.7

Overall

8.1

Food

7.2

Reviews

1 / 10

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

Delta
8.0
Very good
8,521 reviews
Southwest
8.1
Very good
4,662 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Entertainment

7.7

Overall

8.1

Food

7.2

Reviews

1 / 10

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

United Airlines
7.4
Good
8,985 reviews
Southwest
8.1
Very good
4,662 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Entertainment

7.7

Overall

8.1

Food

7.2

Reviews

1 / 10

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

American Airlines
7.2
Good
10,000 reviews
Southwest
8.1
Very good
4,662 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Entertainment

7.7

Overall

8.1

Food

7.2

Reviews

1 / 10

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 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 89 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 ($44), Southwest ($109), and United Airlines ($129).

  • 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 Air Canada (86%), United Airlines (86%) or Southwest (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 $115, our data shows the cheapest flight currently is $42. When looking at the most popular route, (Denver Intl - Ontario), you can expect to pay $63 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 $310). 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

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Colorado to Ontario

See prices for flight routes from nearby airports that may be better suited for you.
John F Kennedy Intl to Las Vegas flights
John F Kennedy Intl to Los Angeles flights
Newark to Los Angeles flights
O'Hare Intl to Las Vegas flights
Dallas/Fort Worth to Las Vegas flights
John F Kennedy Intl to San Francisco flights
Minneapolis to Las Vegas flights
Denver to Las Vegas flights
Seattle to Las Vegas flights
San Francisco to Las Vegas flights
Seattle to Los Angeles flights
Newark to Las Vegas flights
Dallas/Fort Worth to Los Angeles flights
Dulles Intl to Las Vegas flights
Newark to San Francisco flights
Atlanta to Las Vegas flights
Los Angeles to Las Vegas flights
Boston to Las Vegas flights
O'Hare Intl to Los Angeles flights
Reagan-National to Los Angeles flights
LaGuardia to Las Vegas flights
LaGuardia to Los Angeles flights
Seattle to San Diego flights
Detroit to Las Vegas flights
Santa Ana to Las Vegas flights
Seattle to Santa Ana flights
Dulles Intl to Los Angeles flights
Baltimore to Las Vegas flights
Boston to Los Angeles flights
Seattle to Ontario flights
Baltimore to Los Angeles flights
Burbank to Las Vegas flights
Reagan-National to Las Vegas flights
Midway to Las Vegas flights
Seattle to San Francisco flights
Hobby to Las Vegas flights
San Francisco to Los Angeles flights
Los Angeles to San Francisco flights
San Jose to Las Vegas flights
O'Hare Intl to San Francisco flights
Philadelphia to Las Vegas flights
George Bush Intcntl to Las Vegas flights
Orlando to Las Vegas flights
Hobby to Los Angeles flights
Oakland to Las Vegas flights
Portland to Los Angeles flights
LaGuardia to San Francisco flights
Salt Lake City to Los Angeles flights
Austin to Las Vegas flights
Reagan-National to San Francisco flights

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 January 21, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$47Average$124FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$137Average$402FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$177Average$343FlexibilityNo cancel feeOn-time63%
DeltaCheapest$250Average$380FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$278Average$378FlexibilityNo cancel feeOn-time71%
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.