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

As of March 2026, 42 flights take off from Colorado and land in Illinois each day. The most common flight departure time for this route is 12:00PM, with 48% of daily flights taking off at noon.

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

Southwest, United Airlines, and Delta are the most popular carriers operating from Colorado to Illinois

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

The number of flights available between Colorado and Illinois is 297 per week as of March 2026. The most frequent departure day is Wed, with 29% of weekly flights leaving on this day.

How long is the flight from Colorado to Illinois?

The flight from Colorado to Illinois depends on which airports you’re departing and arriving from and whether or not you have a layover. If you fly from Denver (a popular airport in Colorado) to Chicago O'Hare Intl Airport (the most popular airport in Illinois), then the flight time is 2h 30m on average. If you fly from Colorado Springs (another popular airport in Colorado) to Chicago O'Hare Intl Airport, then the average flight time is 2h 41m.

What airlines fly to Illinois?

United Airlines, American Airlines and Frontier are the top three most popular airlines that fly to Illinois from Colorado according to our data. United Airlines is the first choice among our users, with 35% of people opting to fly with this airline when traveling to Illinois. Keep in mind that there are 6 different airlines that fly to Illinois 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 Illinois?

Prices for flights from Colorado to Illinois are updated daily.

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

As of March 2026, there are 6 operators available to choose from for flights from Colorado to Illinois.

How old do you have to be to fly from Colorado to Illinois?

The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Colorado to Illinois.

What documentation or ID do you need to fly to Illinois?

The required travel and health documents for your Illinois trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Illinois. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

$43 Cheap Flights from Colorado to Illinois in 2026

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Find the cheapest flights from Colorado to Illinois

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One-way

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Cheap round-trip flights

Enter your travel dates to find the best prices.

6:40 am - 9:48 am

DEN

STL

2h 08mnonstop

8:06 pm - 9:39 pm

STL

DEN

2h 33mnonstop

$87Frontier

Sat, Apr 11 - Fri, Apr 17

6:40 am - 9:48 am

DEN

STL

2h 08mnonstop

8:16 pm - 9:49 pm

STL

DEN

2h 33mnonstop

$88Frontier

Wed, Apr 1 - Sat, Apr 4

6:40 am - 9:48 am

DEN

STL

2h 08mnonstop

8:17 pm - 9:50 pm

STL

DEN

2h 33mnonstop

$91Frontier

Mon, Apr 13 - Sat, Apr 18

5:15 pm - 12:10 am

COS

MDW

5h 55m

1 stop

10:15 am - 6:05 pm

MDW

COS

8h 50m

1 stop

$211Southwest

Tue, Mar 31 - Tue, Apr 7

6:00 am - 1:55 pm

COS

ORD

6h 55m

1 stop

4:50 pm - 9:00 pm

ORD

COS

5h 10m

1 stop

$211Southwest

Wed, Mar 25 - Tue, Mar 31

1:33 pm - 9:20 pm

COS

ORD

6h 47m

1 stop

7:45 pm - 9:54 pm

ORD

COS

3h 09mnonstop

$219United Airlines

Tue, Mar 31 - Tue, Apr 7

5:55 pm - 9:19 pm

DEN

PIA

2h 24mnonstop

1:20 pm - 6:06 pm

PIA

DEN

5h 46m

1 stop

$219United Airlines

Tue, Apr 21 - Tue, Apr 28

12:07 pm - 3:50 pm

COS

ORD

2h 43mnonstop

9:45 am - 11:36 am

ORD

COS

2h 51mnonstop

$229American Airlines

Tue, Aug 25 - Sat, Aug 29

4:58 pm - 11:48 pm

GJT

ORD

5h 50m

1 stop

5:00 am - 12:12 pm

ORD

GJT

8h 12m

1 stop

$239American Airlines

Fri, Apr 10 - Tue, Apr 14

4:27 pm - 7:30 pm

DEN

PIA

2h 03mnonstop

5:13 pm - 6:36 pm

PIA

DEN

2h 23mnonstop

$255Allegiant Air

Thu, May 21 - Thu, May 28

American Airlines flights from Colorado to Illinois

Our best American Airlines deals on Colorado to Illinois flight tickets

American Airlines

Aug 25

COS12:07 pmColorado Springs

2h 43m

ORD3:50 pmChicago O'Hare Intl

Aug 29

ORD9:45 amChicago O'Hare Intl

2h 51m

COS11:36 amColorado Springs

$229

American Airlines

Apr 10

GJT4:58 pmGrand Junction Regnl

5h 50m

1 stop

ORD11:48 pmChicago O'Hare Intl

Apr 14

ORD5:00 amChicago O'Hare Intl

8h 12m

1 stop

GJT12:12 pmGrand Junction Regnl

$239

American Airlines

Mar 27

COS12:30 pmColorado Springs

2h 40m

ORD4:10 pmChicago O'Hare Intl

Mar 31

ORD7:00 amChicago O'Hare Intl

7h 08m

1 stop

COS1:08 pmColorado Springs

$240

Delta flights from Colorado to Illinois

Our best Delta deals on Colorado to Illinois flight tickets

Delta

Apr 24

DEN6:10 amDenver Intl

5h 33m

1 stop

MDW12:43 pmChicago Midway

Apr 27

MDW6:00 amChicago Midway

8h 32m

1 stop

DEN1:32 pmDenver Intl

$217

Delta

Mar 31

COS6:20 amColorado Springs

11h 14m

2 stops

ORD6:34 pmChicago O'Hare Intl

Apr 7

ORD12:15 pmChicago O'Hare Intl

9h 13m

2 stops

COS8:28 pmColorado Springs

$241

Delta

Apr 15

COS1:14 pmColorado Springs

7h 11m

1 stop

ORD9:25 pmChicago O'Hare Intl

Apr 22

ORD2:25 pmChicago O'Hare Intl

6h 55m

1 stop

COS8:20 pmColorado Springs

$247

Fly from

Fly to

Route

Depart

Return

Price

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Sat 4/11

6:40 am-9:48 am

Nonstop2h 08m

Lambert-St Louis

Fri 4/17

8:06 pm-9:39 pm

Nonstop2h 33m

$87

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Wed 4/1

6:40 am-9:48 am

Nonstop2h 08m

Lambert-St Louis

Sat 4/4

8:16 pm-9:49 pm

Nonstop2h 33m

$88

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Mon 4/13

6:40 am-9:48 am

Nonstop2h 08m

Lambert-St Louis

Sat 4/18

8:17 pm-9:50 pm

Nonstop2h 33m

$91

Colorado SpringsChicago

COS - MDW

COSMDW

Colorado Springs

Tue 3/31

5:15 pm-12:10 am

1 stop5h 55m

Chicago Midway

Tue 4/7

10:15 am-6:05 pm

1 stop8h 50m

$211

Colorado SpringsChicago

COS - ORD

COSORD

Colorado Springs

Wed 3/25

6:00 am-1:55 pm

1 stop6h 55m

Chicago O'Hare Intl

Tue 3/31

4:50 pm-9:00 pm

1 stop5h 10m

$211

Colorado SpringsChicago

COS - ORD

COSORD

Colorado Springs

Tue 3/31

1:33 pm-9:20 pm

1 stop6h 47m

Chicago O'Hare Intl

Tue 4/7

7:45 pm-9:54 pm

Nonstop3h 09m

$219

DenverPeoria

DEN - PIA

DENPIA

Denver Intl

Tue 4/21

5:55 pm-9:19 pm

Nonstop2h 24m

Greater Peoria

Tue 4/28

1:20 pm-6:06 pm

1 stop5h 46m

$219

Colorado SpringsChicago

COS - ORD

COSORD

Colorado Springs

Tue 8/25

12:07 pm-3:50 pm

Nonstop2h 43m

Chicago O'Hare Intl

Sat 8/29

9:45 am-11:36 am

Nonstop2h 51m

$229

Grand JunctionChicago

GJT - ORD

GJTORD

Grand Junction Regnl

Fri 4/10

4:58 pm-11:48 pm

1 stop5h 50m

Chicago O'Hare Intl

Tue 4/14

5:00 am-12:12 pm

1 stop8h 12m

$239

DenverPeoria

DEN - PIA

DENPIA

Denver Intl

Thu 5/21

4:27 pm-7:30 pm

Nonstop2h 03m

Greater Peoria

Thu 5/28

5:13 pm-6:36 pm

Nonstop2h 23m

$255

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

How to get the cheapest flight ticket from Colorado to Illinois

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 Illinois?

The cheapest month to fly to Illinois from Colorado is in August. Flight prices, which tend to average around $196, are often lower during this time because this is during the off-season. If you aren’t able to travel to Illinois during the month of August, then flying in September is also cheap. Prices for this month can be found on momondo for an average of $197.

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

The cheapest day to depart from Colorado to Illinois is on a Thursday when prices can be found for as low as $295. Flights from Colorado to Illinois on a Sunday will generally be more expensive and average around $519. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

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

Our most recent data shows that the best time of day to fly to Illinois is in the evening. Flights from Colorado to Illinois during this time can be as low as $205. Flights at noon are often more expensive with an average ticket price of $564.

What is the cheapest Colorado to Illinois flight route?

Fly from Denver Intl to Chicago O'Hare Intl for the best Colorado - Illinois flight prices

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

You are more likely to see cheaper flights to Illinois from Colorado when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around $252 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from Colorado for as low as $197 on momondo.

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

There are 4 cabin classes available to choose from on Colorado to Illinois 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 Illinois flights?

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

Cheap Colorado to Illinois flight deals and tips

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

Best Price Found	$145
Fastest flight time	1h 58m
Direct flights	Every day
Airports in Illinois	98 airports

The best one-way flight to Illinois from Colorado in the past 72 hours is $145. The best round-trip flight deal from Colorado to Illinois found on momondo in the last 72 hours is $263.

The fastest flight from Colorado to Illinois takes 1h 58m

Direct flights go from Colorado to Illinois every day.

There are 98 airports in Illinois. From Colorado there are direct flights to Greater Peoria (PIA), Lambert-St Louis (STL).

Search flight deals

When did momondo last update prices for flights from Colorado to Illinois?
Prices for flights from Colorado to Illinois are updated daily.
How many operators does momondo search for flights from Colorado to Illinois?
As of March 2026, there are 6 operators available to choose from for flights from Colorado to Illinois.
How old do you have to be to fly from Colorado to Illinois?
The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Colorado to Illinois.
What documentation or ID do you need to fly to Illinois?
The required travel and health documents for your Illinois trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Illinois. We recommend that you seek guidance from your airline or a reliable third party such as IATA.
What is the most popular plane model from Colorado to Illinois?
Based on momondo bookings for this flight route, the most popular plane model on flight routes from Colorado to Illinois is Airbus A321neo (15.60% of total bookings). The next most popular plane models are Boeing 737-800 (11.48%), Boeing 757-300 (10.75%), and Boeing 737-900 (8.61%).

Best airlines flying from Colorado to Illinois

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

Airline	Rating	Free Cancellation	Price
Allegiant Air	PriceFrom $57	Free Cancellation	Rating 7.3 717 reviews	Search Allegiant Air flights
Frontier	PriceFrom $70	Free Cancellation	Rating 5.7 3,041 reviews	Search Frontier flights
JetBlue	PriceFrom $126	Free Cancellation	Rating 7.2 2,897 reviews	Search JetBlue flights
Southwest	PriceFrom $155	Free Cancellation	Rating 8.0 4,306 reviews	Search Southwest flights
American Airlines	PriceFrom $157	Free Cancellation	Rating 7.1 11,380 reviews	Search American Airlines flights
United Airlines	PriceFrom $159	Free Cancellation	Rating 7.4 9,388 reviews	Search United Airlines flights

Why use momondo?

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

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Colorado to Illinois. Millions of users trust and use momondo every year so you are in good hands.

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

Flights from Colorado to Illinois with flexible booking policies can be found by using the search form above and then selecting our dedicated flexible booking filter, which will highlight only the flights where this policy is applied.

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

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Illinois from Colorado.

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

If you are not ready to book a flight from Colorado to Illinois now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Illinois and let you know when they change.

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Popular cities in Illinois

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Cheap flights from Colorado to Illinois from $43

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 Illinois departing on 5/10. 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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How to get the cheapest flight ticket from Colorado to Illinois

What is the cheapest month to fly to Illinois?

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

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

What is the cheapest Colorado to Illinois flight route?

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

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

Can stopping save me money on Colorado to Illinois flights?

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

What airlines fly to Illinois?

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

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

How long is the flight from Colorado to Illinois?

Cheap Colorado to Illinois flight deals and tips

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

Best Price Found

Fastest flight time

Direct flights

Airports in Illinois

Best airlines flying from Colorado to Illinois

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

Why use momondo?

An easier way to manage your Illinois 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 Illinois

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According to popular flight searches on momondo this year

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