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$67+ Cheap flights from Ontario (ONT) to Colorado

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 12/4. Fares are subject to change and may not be available on all flights or dates of travel.
ONT — DEN
nov 9 — nov 161
sön 11/9
sön 11/16
1 adult, Economy
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Find flight deals from Ontario to Colorado

Cheapest flights from Ontario to Colorado
Explore the most affordable flight options available from Ontario to Colorado. Find the lowest fares from popular airlines and budget airlines, with prices last updated on oktober 10, 2025.

This CheapOair deal was found by Cheapflights users on 10/9. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
tors 10/166:53 amONT - DEN
Nonstop2h 25mFrontier
lör 10/1810:29 pmDEN - ONT
Nonstop2h 21mFrontier
Deal found 10/9$88
This Frontier deal was found by Cheapflights users on 10/9. 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.
sön 11/25:53 amONT - DEN
Nonstop2h 25mFrontier
ons 11/58:05 pmDEN - ONT
Nonstop2h 22mFrontier
Deal found 10/9$90
This Cheapflightsfares deal was found by Cheapflights users on 10/7. 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.
sön 11/25:53 amONT - DEN
Nonstop2h 25mFrontier
tis 11/48:05 pmDEN - ONT
Nonstop2h 22mFrontier
Deal found 10/7$92
This Frontier deal was found by Cheapflights users on 10/8. 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.
tis 10/217:04 amONT - DEN
Nonstop2h 27mFrontier
ons 10/229:14 pmDEN - ONT
1 stop11h 35mFrontier
Deal found 10/8$93
This Cheapflightsfares deal was found by Cheapflights users on 10/8. 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.
tors 12/46:30 amONT - DEN
1 stop4h 44mFrontier
sön 12/79:30 amDEN - ONT
Nonstop2h 27mFrontier
Deal found 10/8$94
This Cheapflightsfares deal was found by Cheapflights users on 10/8. 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.
mån 11/36:53 amONT - DEN
Nonstop2h 25mFrontier
ons 11/128:07 pmDEN - ONT
Nonstop2h 22mFrontier
Deal found 10/8$95
This CheapOair deal was found by Cheapflights users on 10/8. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
ons 11/128:45 amONT - DEN
Nonstop2h 22mFrontier
mån 11/1710:29 pmDEN - ONT
Nonstop2h 21mFrontier
Deal found 10/8$96
This Frontier deal was found by Cheapflights users on 10/9. 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.
tis 10/217:04 amONT - DEN
Nonstop2h 27mFrontier
mån 11/39:48 amDEN - ONT
Nonstop2h 22mFrontier
Deal found 10/9$97
This Frontier deal was found by Cheapflights users on 10/9. 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.
tors 10/166:53 amONT - DEN
Nonstop2h 25mFrontier
tors 10/238:15 amDEN - ONT
Nonstop2h 20mFrontier
Deal found 10/9$98
This Frontier deal was found by Cheapflights users on 10/9. 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.
sön 10/266:53 amONT - DEN
Nonstop2h 25mFrontier
tis 11/48:05 pmDEN - ONT
Nonstop2h 22mFrontier
Deal found 10/9$99
This CheapOair deal was found by Cheapflights users on 10/7. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lör 11/112:05 pmONT - DEN
Nonstop2h 29mFrontier
sön 11/29:48 amDEN - ONT
Nonstop2h 22mFrontier
Deal found 10/7$100
This Frontier deal was found by Cheapflights users on 10/8. 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.
tors 11/66:53 amONT - DEN
Nonstop2h 25mFrontier
lör 11/89:48 amDEN - ONT
Nonstop2h 22mFrontier
Deal found 10/8$101

Cheap flight deals from Ontario to Colorado

Keep the following information in mind while searching for Ontario to Colorado flight deals. Data was last updated oktober 10, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$90
(Frontier)

One-way from

$67
(Kiwi.com)

Popular in

June

Cheapest in

January

Average price

$182

Good round-trip deal

$179 or less

Good one-way deal

$111 or less
Provider with most accurate pricing for Los Angeles-Denver Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Los Angeles-Denver Intl flights.
Search Deals
From Ontario to Colorado
Search Deals
One-way flight from Ontario to Colorado
Search Deals
Highest demand for flights based on searches. 9% potential increase in price ($19 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 1% potential price decrease ($4 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 2025
Search Deals
Price to beat on a round-trip flight from Ontario to Colorado.
Search Deals
Price to beat on a one-way flight from Ontario to Colorado.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Ontario to Colorado 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 oktober 10, 2025.
Use the filters below to find and compare flights from Ontario to Colorado that are best for you.

Fly from

Ontario

Fly to

Colorado

Route

Depart

Return

Price

OntarioDenver

ONT - DEN

ONTDEN

Ontario

sön 12/14

8:30 am-11:40 am

Nonstop2h 10m

Denver Intl

sön 12/14

10:45 pm-12:05 am

Nonstop2h 20m

$197

OntarioDenver

ONT - DEN

ONTDEN

Ontario

tors 10/30

5:05 am-8:19 am

Nonstop2h 14m

Denver Intl

sön 11/2

7:21 pm-8:44 pm

Nonstop2h 23m

$197

OntarioDurango

ONT - DRO

ONTDRO

Ontario

ons 10/22

1:15 pm-8:33 pm

1 stop6h 18m

Durango La Plata County

lör 10/25

3:25 pm-8:24 pm

1 stop5h 59m

$200

OntarioGrand Junction

ONT - GJT

ONTGJT

Ontario

fre 10/24

7:27 pm-12:20 am

1 stop3h 53m

Grand Junction Regnl

sön 10/26

5:00 am-9:19 am

1 stop5h 19m

$211

OntarioGrand Junction

ONT - GJT

ONTGJT

Ontario

lör 10/25

6:15 am-11:45 am

1 stop4h 30m

Grand Junction Regnl

ons 10/29

5:00 am-9:19 am

1 stop5h 19m

$211

OntarioMontrose

ONT - MTJ

ONTMTJ

Ontario

fre 10/24

1:15 pm-8:19 pm

1 stop6h 04m

Montrose County

tis 10/28

1:30 pm-10:51 pm

2 stops10h 21m

$214

OntarioGrand Junction

ONT - GJT

ONTGJT

Ontario

fre 10/24

1:15 pm-8:22 pm

1 stop6h 07m

Grand Junction Regnl

tis 10/28

1:35 pm-10:51 pm

2 stops10h 16m

$216

OntarioColorado Springs

ONT - COS

ONTCOS

Ontario

tors 12/4

4:49 pm-10:16 pm

1 stop4h 27m

Colorado Springs

ons 12/10

6:00 pm-11:58 pm

1 stop6h 58m

$217

OntarioColorado Springs

ONT - COS

ONTCOS

Ontario

ons 12/3

4:49 pm-10:16 pm

1 stop4h 27m

Colorado Springs

tis 12/9

6:00 pm-11:58 pm

1 stop6h 58m

$217

OntarioColorado Springs

ONT - COS

ONTCOS

Ontario

tis 11/4

4:35 pm-10:10 pm

1 stop4h 35m

Colorado Springs

tis 11/11

6:02 pm-11:52 pm

1 stop6h 50m

$217

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/7

Showing 1-10 of 60 results
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Best time to book a flight from Ontario to Colorado

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

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

Currently, March is the cheapest month in which you can book a flight from Ontario to Colorado (average of $36). Flying from Ontario to Colorado in September is currently the most expensive (average of $76). 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 CO?

Find hourly flight availability from Ontario to Colorado. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated oktober 10, 2025.

It’s typically best to fly out from Ontario to Colorado in the afternoon. Doing so could potentially save you 38% on the flight price compared to flying in the evening, which is usually more expensive.

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

Use this chart to determine the cheapest time to fly round-trip from Ontario to Colorado. Price data was last updated on December 16, 2024.

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

Weekly flight availability from Ontario to Colorado

Explore weekly flight availability from Ontario to Colorado. 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 oktober 10, 2025.

The most flights from ONT to USCO are scheduled on a Thursday (12 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (2 on average).

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

Reviews of airlines servicing Colorado

Get insights into the airlines that provide service to Colorado. 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 Colorado. Reviews last updated oktober 10, 2025.
See what other customers who have flown with Southwest, Delta, and United Airlines from Ontario to Colorado have to say. Users can see the overall rating for each airline as well as how each is rated in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,237 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Southwest
8.0
Very good
4,237 reviews
Southwest
8.0
Very good
4,237 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Delta
8.0
Very good
7,969 reviews
Southwest
8.0
Very good
4,237 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
United Airlines
7.4
Good
8,968 reviews
Southwest
8.0
Very good
4,237 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
American Airlines
7.2
Good
11,043 reviews
Southwest
8.0
Very good
4,237 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Frontier
5.8
Fair
3,143 reviews
Southwest
8.0
Very good
4,237 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.

Related info for your journey

Find useful and relevant information for your journey from Ontario to Colorado. 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 from for flights from Ontario to Colorado?

    Ontario (ONT), located 3.1 mi from the city center, is the airport you fly out of when you book flights from Ontario to Colorado.

  • How popular is this Ontario to Colorado flight route?

    The Ontario to Colorado flight path was viewed by 343 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • How long is the flight from Ontario to Colorado?

    Airlines like Southwest, United Airlines, and American Airlines fly from Ontario to Colorado in about 2h 10m. The time it takes to get you to your destination can typically vary by up to 1h 43m. The distance from Ontario to Colorado is about 817 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

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

    The most popular route from Ontario to Colorado is Ontario - Denver Intl. You may also consider Ontario - Colorado Springs or Ontario - Aspen Pitkin County.

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

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Ontario to Colorado on time: Frontier (73%), Southwest (72%), United Airlines (71%).

  • What are the cheapest flights from Ontario to Colorado?

    Looking at all options, your cheapest flight can be booked for $77. While the most popular route (Ontario - Denver Intl) can be booked for $56 on average, our data indicates $490 when flying from Ontario to Colorado.

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

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

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

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

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

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

    Currently, March is the cheapest month in which you can book a flight from Ontario to Colorado (average of $36). Flying from Ontario to Colorado in September is currently the most expensive (average of $76). 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 Ontario to Colorado

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Top 5 airlines flying from Ontario to Colorado

Discover the top 5 airlines that operate flights from Ontario to Colorado. 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 oktober 10, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$58Average$138FlexibilityNo cancel feeOn-time62%
DeltaCheapest$109Average$273FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$120Average$351FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$131Average$378FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$268Average$390FlexibilityNo cancel feeOn-time71%

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