What is the cheapest airline that flies from Colorado to Ontario?

Frontier, American Airlines, and Southwest are the most popular carriers operating from Colorado to Ontario

How many flights depart from Colorado to Ontario on average per week?

As of September 2025, there are 74 flights per week flying from Colorado to Ontario. The most common day of the week flights depart is Mon, with 18% of flights taking off on this day.

How long does it take to fly to Ontario?

Average flight duration from Colorado to Ontario depends on which airport you fly into and out of. Flying from Aspen to Los Angeles is 2h 16m on average, while flying from Montrose to Los Angeles is 2h 20m on average. Los Angeles is the most popular airport in Ontario.

How many flights depart from Colorado to Ontario on average per day?

10 flights are operational daily from Colorado to Ontario as of September 2025. The most popular departure time for this route is 7:00PM, with 40% of flights per day taking off in the evening.

What airlines fly to Ontario?

Frontier, United Airlines and Southwest are the top three most popular airlines that fly to Ontario from Colorado according to our data. Frontier is the first choice among our users, with 53% of people opting to fly with this airline when traveling to Ontario. Keep in mind that there are 7 different airlines that fly to Ontario on a routine basis, so you have a few additional options to choose from.

When did momondo last update prices for flights from Colorado to Ontario Airport?

Prices for flights from Colorado to Ontario Airport refresh daily.

How many operators does momondo search for flights from Colorado to Ontario Airport?

As of September 2025, there are 5 operators available to choose from for flights from Colorado to Ontario Airport.

How old do you have to be to fly from Colorado to Ontario Airport?

Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Colorado to Ontario Airport.

What documentation or ID do you need to fly to Ontario Airport?

The travel and health documents you'll need for your trip to Ontario Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Ontario Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.

$51 Cheap Flights from Colorado to Ontario in 2025/26

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Find the cheapest flights from Colorado to Los Angeles

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

9:30 am - 10:57 amDEN-ONT

2h 27mnonstop

4:02 pm - 7:23 pmONT-DEN

2h 21mnonstop

$82Frontier

Find Deal

Thu, Dec 4 - Sun, Dec 7

10:29 pm - 11:50 pmDEN-ONT

2h 21mnonstop

6:45 am - 10:10 amONT-DEN

2h 25mnonstop

$83Frontier

Find Deal

Sat, Nov 1 - Sun, Nov 9

5:49 pm - 9:20 pmCOS-ONT

4h 31m1 stop

1:15 pm - 7:40 pmONT-COS

5h 25m1 stop

$244Delta

Find Deal

Wed, Oct 29 - Sat, Nov 1

5:49 pm - 9:20 pmCOS-ONT

4h 31m1 stop

7:35 am - 7:40 pmONT-COS

11h 05m2 stops

$249Delta

Find Deal

Wed, Oct 29 - Sat, Nov 1

3:30 pm - 8:58 pmCOS-ONT

6h 28m1 stop

1:20 pm - 9:06 pmONT-COS

6h 46m1 stop

$287United Airlines

Find Deal

Thu, Jan 22 - Mon, Jan 26

3:40 pm - 8:24 pmCOS-ONT

5h 44m1 stop

5:05 am - 10:40 amONT-COS

4h 35m1 stop

$288United Airlines

Find Deal

Thu, Oct 16 - Sat, Oct 18

6:02 am - 11:58 amCOS-ONT

6h 56m1 stop

11:59 pm - 9:47 amONT-COS

8h 48m1 stop

$313American Airlines

Find Deal

Thu, Oct 16 - Sat, Oct 18

6:35 am - 12:00 pmCOS-ONT

6h 25m1 stop

6:10 pm - 11:40 pmONT-COS

4h 30m1 stop

$332Southwest

Find Deal

Thu, Nov 20 - Sun, Nov 23

6:35 pm - 12:05 amCOS-ONT

6h 30m1 stop

10:35 am - 10:40 pmONT-COS

11h 05m1 stop

$337Southwest

Find Deal

Sun, Nov 2 - Fri, Nov 7

4:54 pm - 10:18 pmCOS-ONT

6h 24m1 stop

11:59 pm - 9:47 amONT-COS

8h 48m1 stop

$340American Airlines

Find Deal

Thu, Oct 16 - Sat, Oct 18

Frontier flights from Colorado to Ontario

Our best Frontier deals on Colorado to Ontario flight tickets

Frontier

Dec 4

DEN9:30 amDenver Intl

2h 27m

ONT10:57 amOntario

Dec 7

ONT4:02 pmOntario

2h 21m

DEN7:23 pmDenver Intl

$82

Find similar

Frontier

Nov 1

DEN10:29 pmDenver Intl

2h 21m

ONT11:50 pmOntario

Nov 9

ONT6:45 amOntario

2h 25m

DEN10:10 amDenver Intl

$83

Find similar

Frontier

Oct 11

DEN10:29 pmDenver Intl

2h 21m

ONT11:50 pmOntario

Oct 14

ONT7:04 amOntario

2h 27m

DEN10:31 amDenver Intl

$84

Find similar

Delta flights from Colorado to Ontario

Our best Delta deals on Colorado to Ontario flight tickets

Delta

Oct 29

COS5:49 pmColorado Springs

4h 31m

1 stop

ONT9:20 pmOntario

Nov 1

ONT1:15 pmOntario

5h 25m

1 stop

COS7:40 pmColorado Springs

$244

Find similar

Delta

Oct 29

COS5:49 pmColorado Springs

4h 31m

1 stop

ONT9:20 pmOntario

Nov 1

ONT7:35 amOntario

11h 05m

2 stops

COS7:40 pmColorado Springs

$249

Find similar

Delta

Oct 16

COS5:49 pmColorado Springs

6h 50m

1 stop

ONT11:39 pmOntario

Oct 18

ONT9:50 amOntario

6h 19m

1 stop

COS5:09 pmColorado Springs

$298

Find similar

Fly from

Fly to

Route

Depart

Return

Price

DenverOntario

DEN - ONT

DENONT

Denver Intl

Thu 12/4

9:30 am-10:57 am

Nonstop2h 27m

Ontario

Sun 12/7

4:02 pm-7:23 pm

Nonstop2h 21m

$82

DenverOntario

DEN - ONT

DENONT

Denver Intl

Sat 11/1

10:29 pm-11:50 pm

Nonstop2h 21m

Ontario

Sun 11/9

6:45 am-10:10 am

Nonstop2h 25m

$83

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Wed 10/29

5:49 pm-9:20 pm

1 stop4h 31m

Ontario

Sat 11/1

1:15 pm-7:40 pm

1 stop5h 25m

$244

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Wed 10/29

5:49 pm-9:20 pm

1 stop4h 31m

Ontario

Sat 11/1

7:35 am-7:40 pm

2 stops11h 05m

$249

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Thu 1/22

3:30 pm-8:58 pm

1 stop6h 28m

Ontario

Mon 1/26

1:20 pm-9:06 pm

1 stop6h 46m

$287

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Thu 10/16

3:40 pm-8:24 pm

1 stop5h 44m

Ontario

Sat 10/18

5:05 am-10:40 am

1 stop4h 35m

$288

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Thu 10/16

6:02 am-11:58 am

1 stop6h 56m

Ontario

Sat 10/18

11:59 pm-9:47 am

1 stop8h 48m

$313

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Thu 11/20

6:35 am-12:00 pm

1 stop6h 25m

Ontario

Sun 11/23

6:10 pm-11:40 pm

1 stop4h 30m

$332

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Sun 11/2

6:35 pm-12:05 am

1 stop6h 30m

Ontario

Fri 11/7

10:35 am-10:40 pm

1 stop11h 05m

$337

Colorado SpringsOntario

COS - ONT

COSONT

Colorado Springs

Thu 10/16

4:54 pm-10:18 pm

1 stop6h 24m

Ontario

Sat 10/18

11:59 pm-9:47 am

1 stop8h 48m

$340

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How to get the cheapest flight ticket from Colorado to Ontario

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

Prices

Airlines

Other information

What is the cheapest month to fly to Ontario?

In general, January is the cheapest month to fly from Colorado to Ontario. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $116. If you aren’t able to travel during the month of January, then book flights to Ontario from Colorado during May instead. Flights to Ontario in May, while not as cheap as those in January, still average around $137.

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

The cheapest day to depart on your flight to Ontario is on a Tuesday when prices can be found for as low as $146. This is often the case because there is less demand to fly during this day of the week. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from Colorado to Ontario for around $194.

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

In the evening is the cheapest time of day to fly from Colorado to Ontario when you can find flight prices for as low as $158. Flying to Ontario in the evening is an ideal time because this is during off-peak travel hours. If you have a flexible travel schedule, then try to avoid flying at noon when prices are $197 on average. Flights to Ontario from Colorado at noon are generally more expensive because this time of day is more convenient for travelers’ schedules.

What is the cheapest Colorado to Ontario flight route?

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

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

You are more likely to see cheaper flights to Ontario from Colorado when booking weeks ahead of your departure date. In general, you can expect to find flights to Ontario for around $161 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Ontario from Colorado for as low as $76 on momondo.

What cabin class options are available on Colorado to Ontario flights?

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

Can stopping save me money on Colorado to Ontario flights?

No. A direct flight is the cheapest option for a flight between Colorado to Ontario.

Cheap Colorado to Ontario flight deals and tips

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

Best Price Found	$83
Fastest flight time	2h 15m
Direct flights	Every day
Airports in Ontario	1 airport

The best one-way flight to Ontario from Colorado in the past 72 hours is $83. The best round-trip flight deal from Colorado to Ontario found on momondo in the last 72 hours is $130.

The fastest flight from Colorado to Ontario takes 2h 15m

Direct flights go from Colorado to Ontario every day.

There is 1 airport near Ontario: Ontario (ONT)

Search flight deals

When did momondo last update prices for flights from Colorado to Ontario Airport?
Prices for flights from Colorado to Ontario Airport refresh daily.
How many operators does momondo search for flights from Colorado to Ontario Airport?
As of September 2025, there are 5 operators available to choose from for flights from Colorado to Ontario Airport.
How old do you have to be to fly from Colorado to Ontario Airport?
Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Colorado to Ontario Airport.
What documentation or ID do you need to fly to Ontario Airport?
The travel and health documents you'll need for your trip to Ontario Airport may differ based on your itinerary and personal situation. Typically, you should have several documents on hand, such as a national ID card or driver's license and a passport that is valid for six months after your intended arrival at Ontario Airport. It is always advisable to seek advice from your airline or a trusted third party, such as IATA.
What is the most popular plane model from Colorado to Ontario?
momondo data reveals that the most frequently booked plane model on the route from Colorado to Ontario is Boeing 737 MAX 8, representing 15.64% of all bookings. The subsequent popular models are Airbus A320neo at 14.06%, Airbus A321neo at 13.77%, and Boeing 737-800 at 11.92%.

Best airlines flying from Colorado to Ontario

Compare and see reviews for airlines that fly from Colorado to Ontario with momondo

Airline	Rating	Free Cancellation	Price
Frontier	PriceFrom $61	Free Cancellation	Rating 5.8 3,166 reviews	Search Frontier flights
Southwest	PriceFrom $120	Free Cancellation	Rating 8.0 4,244 reviews	Search Southwest flights
United Airlines	PriceFrom $148	Free Cancellation	Rating 7.4 8,922 reviews	Search United Airlines flights
Delta	PriceFrom $177	Free Cancellation	Rating 7.9 7,971 reviews	Search Delta flights
American Airlines	PriceFrom $218	Free Cancellation	Rating 7.2 10,000 reviews	Search American Airlines flights

Why use momondo?

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

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to Ontario from Colorado.

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

All flight searches from Colorado to Ontario on momondo can be filtered to show those which offer flexible booking policies.

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

Once all potential Colorado to Ontario flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

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

Yes. momondo can track prices for Colorado to Ontario flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

An easier way to manage your Ontario trip

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Cheap flights from Colorado to Los Angeles from $51

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Colorado to Los Angeles departing on 9/30. 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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Our best Delta deals on Colorado to Ontario flight tickets

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How to get the cheapest flight ticket from Colorado to Ontario

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 Ontario?

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

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

What is the cheapest Colorado to Ontario flight route?

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

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

What cabin class options are available on Colorado to Ontario flights?

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

Can stopping save me money on Colorado to Ontario flights?

No. A direct flight is the cheapest option for a flight between Colorado to Ontario.

What is the cheapest airline that flies from Colorado to Ontario?

Frontier, American Airlines, and Southwest are the most popular carriers operating from Colorado to Ontario

What airlines fly to Ontario?

How many flights depart from Colorado to Ontario on average per day?

10 flights are operational daily from Colorado to Ontario as of September 2025. The most popular departure time for this route is 7:00PM, with 40% of flights per day taking off in the evening.

How many flights depart from Colorado to Ontario on average per week?

As of September 2025, there are 74 flights per week flying from Colorado to Ontario. The most common day of the week flights depart is Mon, with 18% of flights taking off on this day.

How long does it take to fly to Ontario?

Average flight duration from Colorado to Ontario depends on which airport you fly into and out of. Flying from Aspen to Los Angeles is 2h 16m on average, while flying from Montrose to Los Angeles is 2h 20m on average. Los Angeles is the most popular airport in Ontario.

Cheap Colorado to Ontario flight deals and tips

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

Best Price Found

Fastest flight time

Direct flights

Airports in Ontario

When did momondo last update prices for flights from Colorado to Ontario Airport?

How many operators does momondo search for flights from Colorado to Ontario Airport?

How old do you have to be to fly from Colorado to Ontario Airport?

What documentation or ID do you need to fly to Ontario Airport?

What is the most popular plane model from Colorado to Ontario?

Best airlines flying from Colorado to Ontario

Compare and see reviews for airlines that fly from Colorado to Ontario with momondo

Why use momondo?

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

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

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

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

An easier way to manage your Ontario 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.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to the United States

Airports servicing California