What airlines fly to Denver?

Frontier, United Airlines and American Airlines are the top three most popular airlines that fly to Denver from Illinois according to our data. Frontier is the first choice among our users, with 32% of people opting to fly with this airline when traveling to Denver. Keep in mind that there are 6 different airlines that fly to Denver on a routine basis, so you have a few additional options to choose from.

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

As of August 2025, 56 flights take off from Illinois and land in Denver each day. The most common flight departure time for this route is 6:00PM, with 35% of daily flights taking off at noon.

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

As of August 2025, there are 396 flights per week flying from Illinois to Denver. The most common day of the week flights depart is Tue, with 22% of flights taking off on this day.

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

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

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 16m on average. On the other hand, flying from Moline to Denver takes 2h 26m 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 August 2025, there are 6 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.

$68 Cheap Flights from Illinois to Denver in 2025

1 adult

0 bags

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Not ready to book? to track prices.

Search flight deals

Find the cheapest flights from Illinois to Denver

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

7:54 pm - 9:23 pmSTL-DEN

2h 29mnonstop

6:00 am - 9:11 amDEN-STL

2h 11mnonstop

$97Frontier

Find Deal

Sat, Aug 30 - Sun, Aug 31

7:55 pm - 9:20 pmSTL-DEN

2h 25mnonstop

6:00 am - 9:06 amDEN-STL

2h 06mnonstop

$98Frontier

Find Deal

Fri, Sep 12 - Tue, Sep 16

7:54 pm - 9:23 pmSTL-DEN

2h 29mnonstop

6:00 am - 9:11 amDEN-STL

2h 11mnonstop

$99Frontier

Find Deal

Sat, Aug 30 - Wed, Sep 3

3:18 pm - 4:34 pmPIA-DEN

2h 16mnonstop

5:24 pm - 8:24 pmDEN-PIA

2h 00mnonstop

$133Allegiant Air

Find Deal

Mon, Sep 8 - Fri, Sep 19

3:18 pm - 4:34 pmPIA-DEN

2h 16mnonstop

5:24 pm - 8:24 pmDEN-PIA

2h 00mnonstop

$145Allegiant Air

Find Deal

Fri, Sep 12 - Fri, Sep 19

5:05 pm - 6:40 pmMDW-DEN

2h 35mnonstop

5:25 am - 8:45 amDEN-MDW

2h 20mnonstop

$160Southwest

Find Deal

Sat, Sep 20 - Mon, Sep 22

9:14 pm - 9:03 amPIA-DEN

12h 49m1 stop

5:24 pm - 8:24 pmDEN-PIA

2h 00mnonstop

$199

Find Deal

Fri, Sep 12 - Fri, Sep 19

8:45 am - 10:26 amPIA-DEN

2h 41mnonstop

5:59 pm - 9:12 pmDEN-PIA

2h 13mnonstop

$209United Airlines

Find Deal

Fri, Sep 12 - Mon, Sep 15

4:35 pm - 5:51 pmPIA-DEN

2h 16mnonstop

8:59 pm - 11:09 amDEN-PIA

13h 10m1 stop

$218

Find Deal

Fri, Oct 3 - Sun, Oct 5

3:55 pm - 9:59 pmPIA-DEN

7h 04m1 stop

5:59 pm - 9:12 pmDEN-PIA

2h 13mnonstop

$219United Airlines

Find Deal

Mon, Sep 8 - Mon, Sep 15

Southwest flights from Illinois to Denver

Our best Southwest deals on Illinois to Denver flight tickets

Southwest

Sep 20

MDW5:05 pmChicago Midway

2h 35m

DEN6:40 pmDenver Intl

Sep 22

DEN5:25 amDenver Intl

2h 20m

MDW8:45 amChicago Midway

$160

Find similar

Southwest

Sep 3

MDW8:20 amChicago Midway

2h 35m

DEN9:55 amDenver Intl

Sep 10

DEN2:50 pmDenver Intl

2h 20m

MDW6:10 pmChicago Midway

$197

Find similar

Southwest

Aug 30

MDW7:25 pmChicago Midway

2h 40m

DEN9:05 pmDenver Intl

Aug 31

DEN6:40 amDenver Intl

2h 20m

MDW10:00 amChicago Midway

$208

Find similar

Frontier flights from Illinois to Denver

Our best Frontier deals on Illinois to Denver flight tickets

Frontier

Aug 30

STL7:54 pmLambert-St Louis

2h 29m

DEN9:23 pmDenver Intl

Aug 31

DEN6:00 amDenver Intl

2h 11m

STL9:11 amLambert-St Louis

$97

Find similar

Frontier

Sep 12

STL7:55 pmLambert-St Louis

2h 25m

DEN9:20 pmDenver Intl

Sep 16

DEN6:00 amDenver Intl

2h 06m

STL9:06 amLambert-St Louis

$98

Find similar

Frontier

Aug 30

STL7:54 pmLambert-St Louis

2h 29m

DEN9:23 pmDenver Intl

Sep 3

DEN6:00 amDenver Intl

2h 11m

STL9:11 amLambert-St Louis

$99

Find similar

Fly from

Fly to

Route

Depart

Return

Price

St. LouisDenver

STL - DEN

STLDEN

Lambert-St Louis

Sat 8/30

7:54 pm-9:23 pm

Nonstop2h 29m

Denver Intl

Sun 8/31

6:00 am-9:11 am

Nonstop2h 11m

$97

St. LouisDenver

STL - DEN

STLDEN

Lambert-St Louis

Fri 9/12

7:55 pm-9:20 pm

Nonstop2h 25m

Denver Intl

Tue 9/16

6:00 am-9:06 am

Nonstop2h 06m

$98

St. LouisDenver

STL - DEN

STLDEN

Lambert-St Louis

Sat 8/30

7:54 pm-9:23 pm

Nonstop2h 29m

Denver Intl

Wed 9/3

6:00 am-9:11 am

Nonstop2h 11m

$99

PeoriaDenver

PIA - DEN

PIADEN

Greater Peoria

Mon 9/8

3:18 pm-4:34 pm

Nonstop2h 16m

Denver Intl

Fri 9/19

5:24 pm-8:24 pm

Nonstop2h 00m

$133

PeoriaDenver

PIA - DEN

PIADEN

Greater Peoria

Fri 9/12

3:18 pm-4:34 pm

Nonstop2h 16m

Denver Intl

Fri 9/19

5:24 pm-8:24 pm

Nonstop2h 00m

$145

ChicagoDenver

MDW - DEN

MDWDEN

Chicago Midway

Sat 9/20

5:05 pm-6:40 pm

Nonstop2h 35m

Denver Intl

Mon 9/22

5:25 am-8:45 am

Nonstop2h 20m

$160

PeoriaDenver

PIA - DEN

PIADEN

Greater Peoria

Fri 9/12

9:14 pm-9:03 am

1 stop12h 49m

Denver Intl

Fri 9/19

5:24 pm-8:24 pm

Nonstop2h 00m

$199

PeoriaDenver

PIA - DEN

PIADEN

Greater Peoria

Fri 9/12

8:45 am-10:26 am

Nonstop2h 41m

Denver Intl

Mon 9/15

5:59 pm-9:12 pm

Nonstop2h 13m

$209

PeoriaDenver

PIA - DEN

PIADEN

Greater Peoria

Fri 10/3

4:35 pm-5:51 pm

Nonstop2h 16m

Denver Intl

Sun 10/5

8:59 pm-11:09 am

1 stop13h 10m

$218

PeoriaDenver

PIA - DEN

PIADEN

Greater Peoria

Mon 9/8

3:55 pm-9:59 pm

1 stop7h 04m

Denver Intl

Mon 9/15

5:59 pm-9:12 pm

Nonstop2h 13m

$219

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 November. Flight prices, which tend to average around $158, are often lower during this time because this is during the off-season. If you don’t want to visit Denver in November, then you should wait until October to fly from Illinois, when ticket prices are also cheap, with an average price of $164.

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 Wednesday when prices can be found for as low as $231. 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 Sunday, with ticket prices averaging around $296.

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 afternoon when flights can be purchased for as low as $226. Flights at noon are often more expensive with an average ticket price of $280.

What is the cheapest Illinois to Denver Intl flight route?

Fly from Greater Peoria to Denver Intl for the best Illinois - Denver Intl flight prices

How far in advance should I book a flight 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 $211 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 $177 on momondo.

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

There are 4 cabin classes available to choose from on Illinois to Denver Intl 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	$98
Fastest flight time	2h 15m
Direct flights	Every day
Airports in Denver	1 airport

The best one-way flight to Denver from Illinois in the past 72 hours is $98. The best round-trip flight deal from Illinois to Denver found on momondo in the last 72 hours is $161.

The fastest flight from Illinois to Denver takes 2h 15m

Direct flights go from Illinois to Denver every day.

There is 1 airport near Denver: Denver Intl (DEN)

Search flight deals

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 August 2025, there are 6 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 Boeing 737-800, representing 11.73% of all bookings. The subsequent popular models are Airbus A321neo at 11.47%, Boeing 737 MAX 8 at 10.95%, and Boeing 737-800 Passenger/BBJ2 (winglets) at 8.49%.

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 $56	Free Cancellation	Rating 5.8 3,207 reviews	Search Frontier flights
Allegiant Air	PriceFrom $81	Free Cancellation	Rating 7.2 701 reviews	Search Allegiant Air flights
American Airlines	PriceFrom $152	Free Cancellation	Rating 7.2 10,000 reviews	Search American Airlines flights
Southwest	PriceFrom $157	Free Cancellation	Rating 8.0 4,246 reviews	Search Southwest flights
United Airlines	PriceFrom $161	Free Cancellation	Rating 7.4 8,928 reviews	Search United Airlines flights
Delta	PriceFrom $228	Free Cancellation	Rating 7.9 7,982 reviews	Search Delta flights

Estes Park

Breckenridge

Black Hawk

Aurora

Fort Collins

Keystone

Cripple Creek

Longmont

Boulder

Manitou Springs

Lakewood

Greeley

Westminster

Thornton

Winter Park

Grand Lake

Copper Mountain

Silverthorne

Frisco

Centennial

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

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.

Start using Trips

Find my bookings

Get notified when prices go down

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

1 adult

Mon 8/25

Mon 9/1

Email me momondo's favorite deals

By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to the United States

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

Popular cities in the United States

Flights to New Yorkfrom $47

Flights to Los Angelesfrom $47

Flights to Miamifrom $63

Flights to Chicagofrom $47

Flights to Orlandofrom $47

Flights to Las Vegasfrom $25

Flights to San Franciscofrom $54

Flights to Washington, D.C.from $52

Flights to Bostonfrom $47

Flights to Atlantafrom $47

Flights to Dallasfrom $53

Flights to Seattlefrom $76

Cheap flights from Illinois to Denver from $68

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 12/4. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Big names and deals

Big names and deals

Filter for what you want

Filter for what you want

Trusted and free

Trusted and free

Price Alerts

Price Alerts

Find the cheapest flights from Illinois to Denver

Cheap round-trip flights

Cheap one-way flights

Cheap last minute flights

Cheap direct flights

Southwest flights from Illinois to Denver

Our best Southwest deals on Illinois to Denver flight tickets

Frontier flights from Illinois to Denver

Our best Frontier deals on Illinois to Denver flight tickets

momondo Fare Finder

Use the filters below to find and compare flights from Illinois to Denver that are best for you.

See travel insights to Denver from

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

What is the cheapest month to fly to Denver?

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 Wednesday when prices can be found for as low as $231. 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 Sunday, with ticket prices averaging around $296.

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 afternoon when flights can be purchased for as low as $226. Flights at noon are often more expensive with an average ticket price of $280.

What is the cheapest Illinois to Denver Intl flight route?

Fly from Greater Peoria to Denver Intl for the best Illinois - Denver Intl flight prices

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

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

There are 4 cabin classes available to choose from on Illinois to Denver Intl 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.

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

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

What airlines fly to Denver?

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

As of August 2025, 56 flights take off from Illinois and land in Denver each day. The most common flight departure time for this route is 6:00PM, with 35% of daily flights taking off at noon.

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

As of August 2025, there are 396 flights per week flying from Illinois to Denver. The most common day of the week flights depart is Tue, with 22% of flights taking off on this day.

How long does it take to fly 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

Fastest flight time

Direct flights

Airports in Denver

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

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

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

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

What is the most popular plane model 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?

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

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

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

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

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