What is the cheapest airline that flies from Illinois to Denver Intl?

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

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

As of September 2026, 82 flights take off from Illinois and land in Denver each day. The most common flight departure time for this route is 3:00PM, with 33% of daily flights taking off at noon.

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

As of September 2026, there are 577 flights per week flying from Illinois to Denver. The most common day of the week flights depart is Mon, with 18% of flights taking off on this day.

What airlines fly to Denver?

United Airlines, American Airlines and Frontier are the top three most popular airlines that fly to Denver from Illinois according to our data. United Airlines is the first choice among our users, with 47% of people opting to fly with this airline when traveling to Denver. Keep in mind that there are 7 different airlines that fly to Denver on a routine basis, so you have a few additional options to choose from.

How long does it take to fly to Denver?

Flight times vary depending on what airport in Illinois you fly out of and what airport in Denver you fly into. For example, flying from Peoria to Denver takes 2h 20m on average. On the other hand, flying from Moline to Denver takes 2h 29m on average. Keep in mind that it’s always quicker to opt for a non-stop flight, so be sure to check momondo if there are any available for your route.

When did momondo last update prices for flights from Illinois to Denver Intl Airport?

Prices for flights from Illinois to Denver Intl Airport are refreshed on a daily basis.

How many operators does momondo search for flights from Illinois to Denver Intl Airport?

As of September 2026, there are 7 operators available to choose from for flights from Illinois to Denver Intl Airport.

How old do you have to be to fly from Illinois to Denver Intl Airport?

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 Illinois to Denver Intl Airport.

What documentation or ID do you need to fly to Denver Intl Airport?

The required travel and health documents for your Denver Intl Airport 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 Denver Intl Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

$78 Cheap Flights from Illinois to Denver in 2026/27

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Illinois to Denver

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

6:35 pm - 8:22 amSTL Lambert-St Louis-DEN Denver Intl

14h 47m1 stop Atlanta Hartsfield-Jackson

10:43 am - 5:40 pmDEN Denver Intl-STL Lambert-St Louis

5h 57m1 stop Atlanta Hartsfield-Jackson

$137Frontier

Mon, Oct 26 - Wed, Oct 28

6:44 pm - 8:22 amSTL Lambert-St Louis-DEN Denver Intl

14h 38m1 stop Atlanta Hartsfield-Jackson

10:43 am - 5:40 pmDEN Denver Intl-STL Lambert-St Louis

5h 57m1 stop Atlanta Hartsfield-Jackson

$138Frontier

Mon, Nov 16 - Wed, Nov 18

8:43 pm - 10:44 pmORD Chicago O'Hare Intl-DEN Denver Intl

3h 01mnonstop

10:16 am - 5:42 pmDEN Denver Intl-ORD Chicago O'Hare Intl

6h 26m1 stop Minneapolis St Paul

$175Multiple Airlines

Tue, Dec 8 - Tue, Dec 29

10:35 pm - 12:32 amORD Chicago O'Hare Intl-DEN Denver Intl

2h 57mnonstop

7:21 am - 11:05 amDEN Denver Intl-ORD Chicago O'Hare Intl

2h 44mnonstop

$189American Airlines

Sat, Dec 19 - Tue, Dec 22

11:54 am - 1:53 pmORD Chicago O'Hare Intl-DEN Denver Intl

2h 59mnonstop

8:00 am - 11:45 amDEN Denver Intl-ORD Chicago O'Hare Intl

2h 45mnonstop

$189American Airlines

Sat, Jan 30 - Wed, Feb 3

3:50 pm - 5:50 pmORD Chicago O'Hare Intl-DEN Denver Intl

3h 00mnonstop

7:10 pm - 10:46 pmDEN Denver Intl-ORD Chicago O'Hare Intl

2h 36mnonstop

$189United Airlines

Tue, Oct 6 - Wed, Oct 7

5:51 pm - 7:45 pmORD Chicago O'Hare Intl-DEN Denver Intl

2h 54mnonstop

6:10 pm - 9:52 pmDEN Denver Intl-ORD Chicago O'Hare Intl

2h 42mnonstop

$189United Airlines

Tue, Oct 6 - Sat, Oct 10

6:05 am - 8:00 amMDW Chicago Midway-DEN Denver Intl

2h 55mnonstop

4:15 pm - 7:35 pmDEN Denver Intl-MDW Chicago Midway

2h 20mnonstop

$189Southwest

Wed, Nov 11 - Wed, Nov 18

6:05 am - 7:45 amMDW Chicago Midway-DEN Denver Intl

2h 40mnonstop

7:00 am - 10:20 amDEN Denver Intl-MDW Chicago Midway

2h 20mnonstop

$189Southwest

Tue, Oct 6 - Tue, Oct 13

8:43 pm - 10:44 pmORD Chicago O'Hare Intl-DEN Denver Intl

3h 01mnonstop

10:16 am - 5:42 pmDEN Denver Intl-ORD Chicago O'Hare Intl

6h 26m1 stop Minneapolis St Paul

$190Multiple Airlines

Thu, Dec 10 - Tue, Dec 29

Cheap last minute flights

Enter your travel dates to find the best prices.

6:30 am - 8:15 amORD Chicago O'Hare Intl-DEN Denver Intl

2h 45mnonstop

4:11 pm - 12:45 amDEN Denver Intl-ORD Chicago O'Hare Intl

7h 34m1 stop Dallas/Fort Worth

$205Frontier

Wed, Sep 23 - Sun, Sep 27

6:30 am - 8:15 amORD Chicago O'Hare Intl-DEN Denver Intl

2h 45mnonstop

8:55 pm - 12:23 amDEN Denver Intl-ORD Chicago O'Hare Intl

2h 28mnonstop

$284Frontier

Wed, Sep 23 - Wed, Sep 30

8:45 am - 10:26 amPIA Greater Peoria-DEN Denver Intl

2h 41mnonstop

5:25 pm - 8:51 pmDEN Denver Intl-PIA Greater Peoria

2h 26mnonstop

$394United Airlines

Sat, Sep 19 - Sat, Sep 26

5:02 am - 8:37 amBMI Bloomington-Normal-DEN Denver Intl

4h 35m1 stop Chicago O'Hare Intl

7:16 am - 12:49 pmDEN Denver Intl-BMI Bloomington-Normal

4h 33m1 stop Chicago O'Hare Intl

$399American Airlines

Tue, Sep 22 - Sun, Sep 27

5:02 am - 10:02 amBMI Bloomington-Normal-DEN Denver Intl

6h 00m1 stop Chicago O'Hare Intl

1:17 pm - 10:08 pmDEN Denver Intl-BMI Bloomington-Normal

7h 51m1 stop Dallas/Fort Worth

$399American Airlines

Sat, Sep 19 - Sat, Sep 26

6:05 am - 12:45 pmPIA Greater Peoria-DEN Denver Intl

7h 40m1 stop Chicago O'Hare Intl

5:25 pm - 8:51 pmDEN Denver Intl-PIA Greater Peoria

2h 26mnonstop

$404United Airlines

Sat, Sep 19 - Sat, Sep 26

12:04 pm - 7:05 pmBMI Bloomington-Normal-DEN Denver Intl

8h 01m1 stop Atlanta Hartsfield-Jackson

3:00 pm - 10:01 pmDEN Denver Intl-BMI Bloomington-Normal

6h 01m1 stop Atlanta Hartsfield-Jackson

$444Delta

Sat, Sep 19 - Sat, Oct 3

4:32 pm - 11:14 pmBMI Bloomington-Normal-DEN Denver Intl

7h 42m1 stop Atlanta Hartsfield-Jackson

3:00 pm - 10:01 pmDEN Denver Intl-BMI Bloomington-Normal

6h 01m1 stop Atlanta Hartsfield-Jackson

$444Delta

Fri, Sep 18 - Sat, Oct 3

6:30 am - 8:15 amORD Chicago O'Hare Intl-DEN Denver Intl

2h 45mnonstop

10:50 pm - 2:15 pmDEN Denver Intl-ORD Chicago O'Hare Intl

14h 25m3 stops Las Vegas Harry Reid Intl Dallas/Fort Worth Kirksville Cannon Memorial

$469Multiple Airlines

Wed, Sep 23 - Wed, Sep 30

2:00 pm - 10:43 pmSTL Lambert-St Louis-DEN Denver Intl

9h 43m2 stops Jonesboro Nashville Intl

6:40 am - 4:34 pmDEN Denver Intl-STL Lambert-St Louis

8h 54m1 stop Orlando

$478Multiple Airlines

Mon, Sep 21 - Mon, Sep 28

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Allegiant Air flights from Illinois to Denver

Our best Allegiant Air deals on Illinois to Denver flight tickets

Allegiant Air

Oct 8

PIA5:24 pmGreater Peoria

2h 20m

DEN6:44 pmDenver Intl

Oct 15

DEN10:20 amDenver Intl

1h 59m

PIA1:19 pmGreater Peoria

$268

Allegiant Air

Oct 8

PIA5:24 pmGreater Peoria

2h 20m

DEN6:44 pmDenver Intl

Oct 15

DEN10:20 amDenver Intl

1h 59m

PIA1:19 pmGreater Peoria

$276

Allegiant Air

Oct 11

PIA5:24 pmGreater Peoria

2h 20m

DEN6:44 pmDenver Intl

Oct 15

DEN10:20 amDenver Intl

1h 59m

PIA1:19 pmGreater Peoria

$278

Frontier flights from Illinois to Denver

Our best Frontier deals on Illinois to Denver flight tickets

Frontier

Oct 26

STL6:35 pmLambert-St Louis

14h 47m

1 stop

DEN8:22 amDenver Intl

Oct 28

DEN10:43 amDenver Intl

5h 57m

1 stop

STL5:40 pmLambert-St Louis

$137

Frontier

Nov 16

STL6:44 pmLambert-St Louis

14h 38m

1 stop

DEN8:22 amDenver Intl

Nov 18

DEN10:43 amDenver Intl

5h 57m

1 stop

STL5:40 pmLambert-St Louis

$138

Frontier

Oct 24

STL7:42 pmLambert-St Louis

2h 27m

DEN9:09 pmDenver Intl

Oct 28

DEN10:43 amDenver Intl

5h 57m

1 stop

STL5:40 pmLambert-St Louis

$141

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisDenver

STL Lambert-St Louis - DEN Denver Intl

STLDEN

Lambert-St Louis

Mon 10/26

6:35 pm-8:22 am

1 stop14h 47m

Denver Intl

Wed 10/28

10:43 am-5:40 pm

1 stop5h 57m

$137

St. LouisDenver

STL Lambert-St Louis - DEN Denver Intl

STLDEN

Lambert-St Louis

Mon 11/16

6:44 pm-8:22 am

1 stop14h 38m

Denver Intl

Wed 11/18

10:43 am-5:40 pm

1 stop5h 57m

$138

ChicagoDenver

ORD Chicago O'Hare Intl - DEN Denver Intl

ORDDEN

Chicago O'Hare Intl

Tue 12/8

8:43 pm-10:44 pm

Nonstop3h 01m

Denver Intl

Tue 12/29

10:16 am-5:42 pm

1 stop6h 26m

$175

ChicagoDenver

ORD Chicago O'Hare Intl - DEN Denver Intl

ORDDEN

Chicago O'Hare Intl

Sat 12/19

10:35 pm-12:32 am

Nonstop2h 57m

Denver Intl

Tue 12/22

7:21 am-11:05 am

Nonstop2h 44m

$189

ChicagoDenver

ORD Chicago O'Hare Intl - DEN Denver Intl

ORDDEN

Chicago O'Hare Intl

Sat 1/30

11:54 am-1:53 pm

Nonstop2h 59m

Denver Intl

Wed 2/3

8:00 am-11:45 am

Nonstop2h 45m

$189

ChicagoDenver

ORD Chicago O'Hare Intl - DEN Denver Intl

ORDDEN

Chicago O'Hare Intl

Tue 10/6

3:50 pm-5:50 pm

Nonstop3h 00m

Denver Intl

Wed 10/7

7:10 pm-10:46 pm

Nonstop2h 36m

$189

ChicagoDenver

ORD Chicago O'Hare Intl - DEN Denver Intl

ORDDEN

Chicago O'Hare Intl

Tue 10/6

5:51 pm-7:45 pm

Nonstop2h 54m

Denver Intl

Sat 10/10

6:10 pm-9:52 pm

Nonstop2h 42m

$189

ChicagoDenver

MDW Chicago Midway - DEN Denver Intl

MDWDEN

Chicago Midway

Wed 11/11

6:05 am-8:00 am

Nonstop2h 55m

Denver Intl

Wed 11/18

4:15 pm-7:35 pm

Nonstop2h 20m

$189

Quickest round-trip

ChicagoDenver

MDW Chicago Midway - DEN Denver Intl

MDWDEN

Chicago Midway

Tue 10/6

6:05 am-7:45 am

Nonstop2h 40m

Denver Intl

Tue 10/13

7:00 am-10:20 am

Nonstop2h 20m

$189

ChicagoDenver

ORD Chicago O'Hare Intl - DEN Denver Intl

ORDDEN

Chicago O'Hare Intl

Thu 12/10

8:43 pm-10:44 pm

Nonstop3h 01m

Denver Intl

Tue 12/29

10:16 am-5:42 pm

1 stop6h 26m

$190

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 Illinois to Denver

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 Denver?

The cheapest month to fly to Denver from Illinois is in January. Flight prices, which tend to average around $226, are often lower during this time because this is during the off-season. If you don’t want to visit Denver in January, then you should wait until November to fly from Illinois, when ticket prices are also cheap, with an average price of $240.

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

The cheapest day to depart on your flight to Denver is on a Friday when prices can be found for as low as $285. This is often the case because there is less demand to fly during this day of the week. The most expensive day to fly to Denver is Monday, with ticket prices averaging around $366.

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

The cheapest time of day to fly to Denver is in the evening when flights can be purchased for as low as $250. Flights in the afternoon are often more expensive with an average ticket price of $332.

What is the cheapest Illinois to Denver Intl flight route?

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

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

You are more likely to see cheaper flights to Denver from Illinois when booking weeks ahead of your departure date. In general, you can expect to find flights to Denver for around $265 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Denver from Illinois for as low as $226 on momondo.

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

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

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

Cheap Illinois to Denver flight deals and tips

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

Best Price Found	$78
Fastest flight time	2h 20m
Direct flights	Every day
Airports in Denver	1 airport

The best one-way flight to Denver from Illinois in the past 72 hours is $78. The best round-trip flight deal from Illinois to Denver found on momondo in the last 72 hours is $137.

The fastest flight from Illinois to Denver takes 2h 20m

Direct flights go from Illinois to Denver every day.

There is 1 airport in Denver. From Illinois there are direct flights to Denver Intl (DEN).

Search flight deals

Frequently asked questions about flying from Illinois to Denver

When did momondo last update prices for flights from Illinois to Denver Intl Airport?
Prices for flights from Illinois to Denver Intl Airport are refreshed on a daily basis.
How many operators does momondo search for flights from Illinois to Denver Intl Airport?
As of September 2026, there are 7 operators available to choose from for flights from Illinois to Denver Intl Airport.
How old do you have to be to fly from Illinois to Denver Intl Airport?
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 Illinois to Denver Intl Airport.
What documentation or ID do you need to fly to Denver Intl Airport?
The required travel and health documents for your Denver Intl Airport 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 Denver Intl Airport. 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 Illinois to Denver?
momondo data reveals that the most frequently booked plane model on the route from Illinois to Denver is Airbus A321neo, representing 17.43% of all bookings. The subsequent popular models are Airbus A321-100/200 at 13.02%, Boeing 737-800 at 11.45%, and Airbus A319 at 9.33%.

Best airlines flying from Illinois to Denver

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

Airline	Rating	Free Cancellation	Price
Frontier	PriceFrom $71	Free Cancellation	Rating 5.6 2,600 reviews	Search Frontier flights
Allegiant Air	PriceFrom $74	Free Cancellation	Rating 7.3 679 reviews	Search Allegiant Air flights
Delta	PriceFrom $105	Free Cancellation	Rating 7.8 8,579 reviews	Search Delta flights
JetBlue	PriceFrom $145	Free Cancellation	Rating 7.1 3,035 reviews	Search JetBlue flights
Southwest	PriceFrom $147	Free Cancellation	Rating 8.0 4,190 reviews	Search Southwest flights
American Airlines	PriceFrom $156	Free Cancellation	Rating 7.1 12,076 reviews	Search American Airlines flights
United Airlines	PriceFrom $173	Free Cancellation	Rating 7.4 10,214 reviews	Search United Airlines flights

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Westminster

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Boulder

Lakewood

Manitou Springs

Greeley

Keystone

Thornton

Centennial

Cripple Creek

Littleton

Englewood

Winter Park

Golden

Frisco

Why use momondo?

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

It is quick and easy to find Illinois to Denver flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to Denver that suits you.

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

Yes. momondo allows you to filter the results for Illinois to Denver flights to just show those with flexible booking policies.

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

momondo helps you find the best flight between Illinois and Denver by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

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

Yes momondo offers price alerts on flights to Denver from Illinois. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.

An easier way to manage your Denver trip

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Airports servicing Colorado

Alamosa Airport

Aspen Pitkin County Airport

Cortez Montezuma County Airport

Colorado Springs Airport

Durango La Plata County Airport

Vail Eagle County Airport

Grand Junction Regnl Airport

Gunnison Airport

Hayden Yampa Valley Airport

Montrose County Airport

Telluride Airport

Cheap flights from Illinois to Denver from $78

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Illinois to Denver departing on 11/16. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Find the cheapest flights from Illinois to Denver

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Allegiant Air flights from Illinois to Denver

Our best Allegiant Air deals on Illinois to Denver flight tickets

Frontier flights from Illinois to Denver

Our best Frontier deals on Illinois to Denver flight tickets

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See travel insights to Denver from

How to get the cheapest flight ticket from Illinois to Denver

What is the cheapest month to fly to Denver?

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

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

What is the cheapest Illinois to Denver Intl flight route?

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

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

Can stopping save me money on Illinois to Denver flights?

What is the cheapest airline that flies from Illinois to Denver Intl?

What airlines fly to Denver?

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

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

How long does it take to fly to Denver?

Cheap Illinois to Denver flight deals and tips

Best Price Found

Fastest flight time

Direct flights

Airports in Denver

Frequently asked questions about flying from Illinois to Denver

Best airlines flying from Illinois to Denver

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

Traveling to a place near Denver?

Why use momondo?

An easier way to manage your Denver 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 Colorado

Fly your favorite airline to Denver

Airlines are sorted and displayed according to clicks in the past 7 days on momondo

Cabin classes currently available on flights to Denver

List of cabin classes available on flights landing in Denver. Availability may vary depending on flight origin and airline.

Popular cities in the United States

Popular flights according to clicks in the last 7 days on momondo

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