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Cheap flights from Denver to Illinois from $35

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Denver to Illinois departing on 12/5. 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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0 bags

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Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
12:09 pm - 10:41 pmSTL-DEN
11h 32m1 stop
$99Frontier
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Sat, Nov 8 - Mon, Nov 10
Frontier Logo
11:59 pm - 10:33 pmDEN-STL
21h 34m1 stop
Frontier Logo
7:43 pm - 9:15 pmSTL-DEN
2h 32mnonstop
$100Frontier
Find Deal
Wed, Jan 7 - Wed, Jan 14
Allegiant Air Logo
5:50 pm - 8:47 pmDEN-PIA
1h 57mnonstop
Allegiant Air Logo
12:09 pm - 1:34 pmPIA-DEN
2h 25mnonstop
$121Allegiant Air
Find Deal
Fri, Nov 14 - Mon, Nov 17
Multiple Airlines Logo
12:59 am - 11:14 amDEN-ORD
9h 15m1 stop
Multiple Airlines Logo
8:28 am - 3:53 pmORD-DEN
8h 25m1 stop
$128Multiple Airlines
Find Deal
Mon, Nov 3 - Tue, Nov 11
Multiple Airlines Logo
12:25 pm - 12:27 amDEN-ORD
11h 02m2 stops
Multiple Airlines Logo
6:00 am - 7:41 amORD-DEN
2h 41mnonstop
$131Multiple Airlines
Find Deal
Sat, Nov 8 - Mon, Nov 10
United Airlines Logo
6:00 am - 9:40 amDEN-ORD
2h 40mnonstop
United Airlines Logo
9:30 pm - 11:15 pmORD-DEN
2h 45mnonstop
$155United Airlines
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Mon, Nov 24 - Mon, Nov 24
Allegiant Air Logo
5:54 pm - 8:51 pmDEN-PIA
1h 57mnonstop
Allegiant Air Logo
3:38 pm - 5:04 pmPIA-DEN
2h 26mnonstop
$155Allegiant Air
Find Deal
Mon, Dec 29 - Mon, Jan 5
American Airlines Logo
7:22 am - 11:06 amDEN-ORD
2h 44mnonstop
American Airlines Logo
8:15 am - 10:08 amORD-DEN
2h 53mnonstop
$161American Airlines
Find Deal
Wed, Dec 3 - Sun, Dec 7
United Airlines Logo
5:45 pm - 8:56 pmDEN-PIA
2h 11mnonstop
United Airlines Logo
8:43 am - 10:35 amPIA-DEN
2h 52mnonstop
$209United Airlines
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Mon, Nov 10 - Thu, Nov 20
American Airlines Logo
12:32 pm - 6:17 pmDEN-MLI
4h 45m1 stop
American Airlines Logo
5:37 pm - 11:20 pmMLI-DEN
6h 43m1 stop
$239American Airlines
Find Deal
Thu, Nov 13 - Sun, Nov 16

American Airlines flights from Denver to Illinois

Our best American Airlines deals on Denver to Illinois flight tickets
American Airlines
Dec 3
DEN7:22 amDenver Intl
2h 44m
ORD11:06 amChicago O'Hare Intl
Dec 7
ORD8:15 amChicago O'Hare Intl
2h 53m
DEN10:08 amDenver Intl
$161
Find similar
American Airlines
Nov 13
DEN12:32 pmDenver Intl
4h 45m
1 stop
MLI6:17 pmMoline Quad-City
Nov 16
MLI5:37 pmMoline Quad-City
6h 43m
1 stop
DEN11:20 pmDenver Intl
$239
Find similar
American Airlines
Nov 5
DEN6:23 amDenver Intl
9h 33m
1 stop
MLI4:56 pmMoline Quad-City
Nov 9
MLI5:37 pmMoline Quad-City
6h 43m
1 stop
DEN11:20 pmDenver Intl
$249
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Frontier flights from Denver to Illinois

Our best Frontier deals on Denver to Illinois flight tickets
Frontier
Nov 8
DEN6:00 amDenver Intl
2h 07m
STL9:07 amLambert-St Louis
Nov 10
STL12:09 pmLambert-St Louis
11h 32m
1 stop
DEN10:41 pmDenver Intl
$99
Find similar
Frontier
Jan 7
DEN11:59 pmDenver Intl
21h 34m
1 stop
STL10:33 pmLambert-St Louis
Jan 14
STL7:43 pmLambert-St Louis
2h 32m
DEN9:15 pmDenver Intl
$100
Find similar
Frontier
Nov 7
DEN6:00 amDenver Intl
2h 07m
STL9:07 amLambert-St Louis
Nov 10
STL7:45 pmLambert-St Louis
2h 28m
DEN9:13 pmDenver Intl
$102
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from Denver to Illinois 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 October 22, 2025.
Use the filters below to find and compare flights from Denver to Illinois that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Sat 11/8

6:00 am-9:07 am

Nonstop2h 07m

Lambert-St Louis

Mon 11/10

12:09 pm-10:41 pm

1 stop11h 32m

$99

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Wed 1/7

11:59 pm-10:33 pm

1 stop21h 34m

Lambert-St Louis

Wed 1/14

7:43 pm-9:15 pm

Nonstop2h 32m

$100

DenverPeoria

DEN - PIA

DENPIA

Denver Intl

Fri 11/14

5:50 pm-8:47 pm

Nonstop1h 57m

Greater Peoria

Mon 11/17

12:09 pm-1:34 pm

Nonstop2h 25m

$121

DenverChicago

DEN - ORD

DENORD

Denver Intl

Mon 11/3

12:59 am-11:14 am

1 stop9h 15m

Chicago O'Hare Intl

Tue 11/11

8:28 am-3:53 pm

1 stop8h 25m

$128

DenverChicago

DEN - ORD

DENORD

Denver Intl

Sat 11/8

12:25 pm-12:27 am

2 stops11h 02m

Chicago O'Hare Intl

Mon 11/10

6:00 am-7:41 am

Nonstop2h 41m

$131

DenverChicago

DEN - ORD

DENORD

Denver Intl

Mon 11/24

6:00 am-9:40 am

Nonstop2h 40m

Chicago O'Hare Intl

Mon 11/24

9:30 pm-11:15 pm

Nonstop2h 45m

$155

DenverPeoria

DEN - PIA

DENPIA

Denver Intl

Mon 12/29

5:54 pm-8:51 pm

Nonstop1h 57m

Greater Peoria

Mon 1/5

3:38 pm-5:04 pm

Nonstop2h 26m

$155

DenverChicago

DEN - ORD

DENORD

Denver Intl

Wed 12/3

7:22 am-11:06 am

Nonstop2h 44m

Chicago O'Hare Intl

Sun 12/7

8:15 am-10:08 am

Nonstop2h 53m

$161

DenverPeoria

DEN - PIA

DENPIA

Denver Intl

Mon 11/10

5:45 pm-8:56 pm

Nonstop2h 11m

Greater Peoria

Thu 11/20

8:43 am-10:35 am

Nonstop2h 52m

$209

DenverMoline

DEN - MLI

DENMLI

Denver Intl

Thu 11/13

12:32 pm-6:17 pm

1 stop4h 45m

Moline Quad-City

Sun 11/16

5:37 pm-11:20 pm

1 stop6h 43m

$239

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Illinois from

How to get the cheapest flight ticket from Denver 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

What is the cheapest month to fly to Illinois?

The cheapest month to fly to Illinois from Denver is in February. Flight prices, which tend to average around $185, 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 February, then flying in January is also cheap. Prices for this month can be found on momondo for an average of $187.

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

The cheapest day to depart from Denver to Illinois is on a Thursday when prices can be found for as low as $303. Flights from Denver to Illinois on a Sunday will generally be more expensive and average around $505. 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 Denver to Illinois during this time can be as low as $198. Flights at noon are often more expensive with an average ticket price of $622.

What is the cheapest Denver Intl to Illinois flight route?

Fly from Denver Intl to Chicago O'Hare Intl for the best Denver Intl - 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 Denver when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around $238 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from Denver for as low as $199 on momondo.

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

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

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

Cheap Denver to Illinois flight deals and tips

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

Best Price Found

$112

Fastest flight time

1h 51m

Direct flights

Every day

Airports in Illinois

2 airports
The best one-way flight to Illinois from Denver in the past 72 hours is $112. The best round-trip flight deal from Denver to Illinois found on momondo in the last 72 hours is $175.
The fastest flight from Denver to Illinois takes 1h 51m
Direct flights go from Denver to Illinois every day.
There are 2 airports near Illinois: Greater Peoria (PIA), Lambert-St Louis (STL)
Search flight deals

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

    Prices for flights from Denver Intl Airport to Illinois are updated daily.

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

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

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Denver Intl Airport to Illinois.

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

    The travel and health documents you'll need for your trip to Illinois 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 Illinois. 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 Denver to Illinois?

Best airlines flying from Denver to Illinois

Compare and see reviews for airlines that fly from Denver to Illinois with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $64Free CancellationRating
5.8
3,130 reviews
Search Frontier flights
Allegiant AirPriceFrom $77Free CancellationRating
7.2
694 reviews
Search Allegiant Air flights
SouthwestPriceFrom $155Free CancellationRating
8.0
4,237 reviews
Search Southwest flights
American AirlinesPriceFrom $156Free CancellationRating
7.2
11,028 reviews
Search American Airlines flights
United AirlinesPriceFrom $165Free CancellationRating
7.4
8,988 reviews
Search United Airlines flights

Why use momondo?

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

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from Denver to Illinois for you.

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

momondo does allow users to show only those flights to Illinois from Denver which offer a flexible booking policy as well as other useful filters and features.

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

Once all potential Denver to Illinois 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 Denver to Illinois right now. Can momondo alert me if prices change?

If you are not ready to book a flight from Denver 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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Fri 11/21
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