Latest deals
Insights
FAQs
Reviews
Price Alerts

Cheap flights from Illinois to Denver from $29

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 1/21. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Filter for what you want

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

Trusted and free

Trusted and free

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

Price Alerts

Price Alerts

Not ready to book? to track prices.
Search flight deals

Find the cheapest flights from Illinois to Denver

Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
7:36 pm - 9:08 pm
STL
-
DEN
2h 32mnonstop
Frontier Logo
9:41 am - 12:50 pm
DEN
-
STL
2h 09mnonstop
$79Frontier
Mon, Jan 19 - Mon, Jan 26
Frontier Logo
2:51 pm - 4:18 pm
STL
-
DEN
2h 27mnonstop
Frontier Logo
10:01 am - 1:09 pm
DEN
-
STL
2h 08mnonstop
$80Frontier
Sat, Feb 21 - Mon, Feb 23
Multiple Airlines Logo
6:57 pm - 8:38 pm
ORD
-
DEN
26h 41m1 stop
Multiple Airlines Logo
2:57 pm - 6:31 pm
DEN
-
ORD
2h 34mnonstop
$118Multiple Airlines
Mon, Feb 2 - Thu, Feb 5
Multiple Airlines Logo
3:38 pm - 5:04 pm
PIA
-
DEN
2h 26mnonstop
Multiple Airlines Logo
12:13 pm - 11:37 am
DEN
-
PIA
22h 24m2 stops
$193Multiple Airlines
Mon, Jan 5 - Mon, Jan 12
United Airlines Logo
8:35 am - 10:20 am
PIA
-
DEN
2h 45mnonstop
United Airlines Logo
5:30 pm - 8:47 pm
DEN
-
PIA
2h 17mnonstop
$209United Airlines
Sat, Jan 17 - Thu, Jan 22
United Airlines Logo
8:46 am - 10:35 am
MLI
-
DEN
2h 49mnonstop
United Airlines Logo
5:25 pm - 8:34 pm
DEN
-
MLI
2h 09mnonstop
$209United Airlines
Wed, Jan 28 - Tue, Feb 3
American Airlines Logo
5:16 pm - 11:16 pm
PIA
-
DEN
7h 00m1 stop
American Airlines Logo
6:23 am - 4:59 pm
DEN
-
PIA
9h 36m1 stop
$229American Airlines
Sat, Jan 24 - Mon, Feb 2
Delta Logo
5:00 pm - 10:18 pm
MLI
-
DEN
6h 18m1 stop
Delta Logo
12:59 am - 10:26 am
DEN
-
MLI
8h 27m1 stop
$229Delta
Wed, May 13 - Tue, May 19
Delta Logo
5:00 pm - 11:51 pm
MLI
-
DEN
7h 51m1 stop
Delta Logo
12:59 am - 10:26 am
DEN
-
MLI
8h 27m1 stop
$249Delta
Fri, May 15 - Tue, May 19
American Airlines Logo
3:34 pm - 10:36 pm
BMI
-
DEN
8h 02m1 stop
American Airlines Logo
9:17 am - 3:04 pm
DEN
-
BMI
4h 47m1 stop
$339American Airlines
Wed, Feb 18 - Sat, Feb 21

Delta flights from Illinois to Denver

Our best Delta deals on Illinois to Denver flight tickets
Delta
May 13
MLI5:00 pmMoline Quad-City
7h 51m
1 stop
DEN11:51 pmDenver Intl
May 24
DEN3:10 pmDenver Intl
6h 21m
1 stop
MLI10:31 pmMoline Quad-City
$229
Find similar
Delta
Jan 1
MDW11:48 amChicago Midway
5h 56m
1 stop
DEN4:44 pmDenver Intl
Jan 6
DEN11:33 amDenver Intl
5h 59m
1 stop
MDW6:32 pmChicago Midway
$243
Find similar
Delta
May 15
MLI5:00 pmMoline Quad-City
7h 51m
1 stop
DEN11:51 pmDenver Intl
May 19
DEN12:59 amDenver Intl
8h 27m
1 stop
MLI10:26 amMoline Quad-City
$249
Find similar

Frontier flights from Illinois to Denver

Our best Frontier deals on Illinois to Denver flight tickets
Frontier
Jan 19
STL7:36 pmLambert-St Louis
2h 32m
DEN9:08 pmDenver Intl
Jan 26
DEN9:41 amDenver Intl
2h 09m
STL12:50 pmLambert-St Louis
$79
Find similar
Frontier
Feb 21
STL2:51 pmLambert-St Louis
2h 27m
DEN4:18 pmDenver Intl
Feb 23
DEN10:01 amDenver Intl
2h 08m
STL1:09 pmLambert-St Louis
$80
Find similar
Frontier
Jan 9
STL7:43 pmLambert-St Louis
2h 32m
DEN9:15 pmDenver Intl
Jan 10
DEN6:50 amDenver Intl
2h 12m
STL10:02 amLambert-St Louis
$83
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Illinois to Denver 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, momondo users made 832,500 searches. Data last updated December 23, 2025.
Use the filters below to find and compare flights from Illinois to Denver that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisDenver

STL - DEN

STLDEN

Lambert-St Louis

Mon 1/19

7:36 pm-9:08 pm

Nonstop2h 32m

Denver Intl

Mon 1/26

9:41 am-12:50 pm

Nonstop2h 09m

$79

St. LouisDenver

STL - DEN

STLDEN

Lambert-St Louis

Sat 2/21

2:51 pm-4:18 pm

Nonstop2h 27m

Denver Intl

Mon 2/23

10:01 am-1:09 pm

Nonstop2h 08m

$80

ChicagoDenver

ORD - DEN

ORDDEN

Chicago O'Hare Intl

Mon 2/2

6:57 pm-8:38 pm

1 stop26h 41m

Denver Intl

Thu 2/5

2:57 pm-6:31 pm

Nonstop2h 34m

$118

PeoriaDenver

PIA - DEN

PIADEN

Greater Peoria

Mon 1/5

3:38 pm-5:04 pm

Nonstop2h 26m

Denver Intl

Mon 1/12

12:13 pm-11:37 am

2 stops22h 24m

$193

PeoriaDenver

PIA - DEN

PIADEN

Greater Peoria

Sat 1/17

8:35 am-10:20 am

Nonstop2h 45m

Denver Intl

Thu 1/22

5:30 pm-8:47 pm

Nonstop2h 17m

$209

MolineDenver

MLI - DEN

MLIDEN

Moline Quad-City

Wed 1/28

8:46 am-10:35 am

Nonstop2h 49m

Denver Intl

Tue 2/3

5:25 pm-8:34 pm

Nonstop2h 09m

$209

PeoriaDenver

PIA - DEN

PIADEN

Greater Peoria

Sat 1/24

5:16 pm-11:16 pm

1 stop7h 00m

Denver Intl

Mon 2/2

6:23 am-4:59 pm

1 stop9h 36m

$229

MolineDenver

MLI - DEN

MLIDEN

Moline Quad-City

Wed 5/13

5:00 pm-10:18 pm

1 stop6h 18m

Denver Intl

Tue 5/19

12:59 am-10:26 am

1 stop8h 27m

$229

MolineDenver

MLI - DEN

MLIDEN

Moline Quad-City

Fri 5/15

5:00 pm-11:51 pm

1 stop7h 51m

Denver Intl

Tue 5/19

12:59 am-10:26 am

1 stop8h 27m

$249

BloomingtonDenver

BMI - DEN

BMIDEN

Bloomington-Normal

Wed 2/18

3:34 pm-10:36 pm

1 stop8h 02m

Denver Intl

Sat 2/21

9:17 am-3:04 pm

1 stop4h 47m

$339

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
1
2

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?

The cheapest month to fly to Denver from Illinois is in January. Flight prices, which tend to average around $182, 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 October to fly from Illinois, when ticket prices are also cheap, with an average price of $183.

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 $229. 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 $285.

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 morning when flights can be purchased for as low as $236. Flights at noon are often more expensive with an average ticket price of $271.

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 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 $219 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 $186 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

$149

Fastest flight time

2h 05m

Direct flights

Every day

Airports in Denver

1 airport
The best one-way flight to Denver from Illinois in the past 72 hours is $149. The best round-trip flight deal from Illinois to Denver found on momondo in the last 72 hours is $187.
The fastest flight from Illinois to Denver takes 2h 05m
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

  • 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?

  • 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?

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
FrontierPriceFrom $59Free CancellationRating
5.8
3,075 reviews
Search Frontier flights
Allegiant AirPriceFrom $74Free CancellationRating
7.2
701 reviews
Search Allegiant Air flights
American AirlinesPriceFrom $153Free CancellationRating
7.2
11,054 reviews
Search American Airlines flights
United AirlinesPriceFrom $155Free CancellationRating
7.4
9,105 reviews
Search United Airlines flights
SouthwestPriceFrom $157Free CancellationRating
8.0
4,253 reviews
Search Southwest flights

Traveling to a place near Denver?

Book flights to Denver if you plan to visit one of these locations
Breckenridge
Estes Park
Black Hawk
Aurora
Fort Collins
Keystone
Cripple Creek
Manitou Springs
Longmont
Boulder
Greeley
Lakewood
Thornton
Westminster
Winter Park
Copper Mountain
Frisco
Silverthorne
Centennial
Grand Lake

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
Thu 1/22
Thu 1/29
By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to the United States