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$53+ Cheap flights from Denver (DEN) to Illinois

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 7/4. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — ORD
may. 28 — jun. 41
mié. 5/28
mié. 6/4
1 adult, Economy
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Cheap flight deals from Denver to Illinois

Keep the following information in mind while searching for Denver to Illinois flight deals. Data was last updated mayo 23, 2025.

Most accurate provider

eDreams
3 stars

Most trusted provider

eDreams
3 stars

Round-trip from

$123
(Kiwi.com)

One-way from

$53
(Booking.com)

Popular in

April

Cheapest in

September

Average price

$212

Good round-trip deal

$140 or less

Good one-way deal

$79 or less
Provider with most accurate pricing for Denver Intl-Chicago (CHI) flight deals.
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Provider most trusted by Cheapflights users for Denver Intl-Chicago (CHI) flights.
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From Denver Intl to Illinois
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One-way flight from Denver Intl to Illinois
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Highest demand for flights based on searches. 12% potential increase in price ($26 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($4 potential savings vs. average RT price).
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Average for round-trip flights in May 2025
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Price to beat on a round-trip flight from Denver Intl to Illinois.
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Price to beat on a one-way flight from Denver Intl to Illinois.
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Find flight deals from Denver to Illinois

Cheapest flights from Denver to Illinois
Explore the most affordable flight options available from Denver to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on mayo 23, 2025.

This Kiwi.com deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 6/216:00 amDEN - STL
Nonstop2h 12mFrontier
sáb. 7/127:29 pmSTL - DEN
Nonstop2h 29mFrontier
Deal found 5/22$127
This Booking.com deal was found by Cheapflights users on 5/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 7/45:58 pmDEN - PIA
Nonstop2h 03mAllegiant Air
lun. 7/73:48 pmPIA - DEN
Nonstop2h 20mAllegiant Air
Deal found 5/23$147
This American Airlines deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 8/1612:07 pmDEN - ORD
Nonstop2h 43mAmerican Airlines
sáb. 8/166:35 pmORD - DEN
Nonstop2h 47mAmerican Airlines
Deal found 5/22$152
This CheapOair deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 9/248:22 pmDEN - ORD
Nonstop2h 31mFrontier
sáb. 9/277:20 amORD - DEN
Nonstop2h 49mFrontier
Deal found 5/22$154
This Kiwi.com deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 9/57:10 pmDEN - MDW
Nonstop2h 28mFrontier
lun. 9/84:29 pmMDW - DEN
Nonstop2h 48mFrontier
Deal found 5/22$155
This Southwest deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 7/91:15 pmDEN - ORD
Nonstop2h 30mSouthwest
mar. 7/1512:40 pmORD - DEN
Nonstop2h 40mSouthwest
Deal found 5/22$157
This Southwest deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 7/99:30 pmDEN - MDW
Nonstop2h 25mSouthwest
mar. 7/155:15 amMDW - DEN
Nonstop2h 35mSouthwest
Deal found 5/22$163
This American Airlines deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 8/237:02 amDEN - STL
1 stop7h 40mAmerican Airlines
mié. 8/279:23 amSTL - DEN
1 stop7h 25mAmerican Airlines
Deal found 5/22$187
This Delta deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 8/2212:59 amDEN - STL
1 stop6h 55mDelta
mié. 8/276:00 amSTL - DEN
1 stop4h 55mDelta
Deal found 5/22$207
This Delta deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 8/136:20 amDEN - ORD
1 stop5h 25mDelta
mar. 8/198:25 amORD - DEN
1 stop5h 24mDelta
Deal found 5/22$217
This Delta deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 7/812:55 amDEN - MDW
1 stop6h 49mDelta
mié. 7/169:24 amMDW - DEN
1 stop7h 08mDelta
Deal found 5/22$217
This United Airlines deal was found by Cheapflights users on 5/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 8/92:44 pmDEN - PIA
1 stop5h 48mUnited Airlines
mar. 8/129:00 amPIA - DEN
Nonstop2h 30mUnited Airlines
Deal found 5/22$219

Cheapflights 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, Cheapflights users made 2,558,603 searches. Data last updated mayo 23, 2025.
Use the filters below to find and compare flights from Denver to Illinois that are best for you.

Fly from

Denver

Fly to

Illinois

Route

Depart

Return

Price

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

sáb. 6/21

6:00 am-9:12 am

Nonstop2h 12m

Lambert-St Louis

sáb. 7/12

7:29 pm-8:58 pm

Nonstop2h 29m

$127

DenverPeoria

DEN - PIA

DENPIA

Denver Intl

vie. 7/4

5:58 pm-9:01 pm

Nonstop2h 03m

Greater Peoria

lun. 7/7

3:48 pm-5:08 pm

Nonstop2h 20m

$147

DenverChicago

DEN - ORD

DENORD

Denver Intl

sáb. 8/16

12:07 pm-3:50 pm

Nonstop2h 43m

Chicago O'Hare Intl

sáb. 8/16

6:35 pm-8:22 pm

Nonstop2h 47m

$152

DenverChicago

DEN - MDW

DENMDW

Denver Intl

vie. 9/5

7:10 pm-10:38 pm

Nonstop2h 28m

Chicago Midway

lun. 9/8

4:29 pm-6:17 pm

Nonstop2h 48m

$155

DenverChicago

DEN - ORD

DENORD

Denver Intl

sáb. 6/21

8:21 pm-11:59 pm

Nonstop2h 38m

Chicago O'Hare Intl

sáb. 6/28

7:00 am-8:49 am

Nonstop2h 49m

$156

DenverChicago

DEN - ORD

DENORD

Denver Intl

mié. 7/9

1:15 pm-4:45 pm

Nonstop2h 30m

Chicago O'Hare Intl

mar. 7/15

7:00 am-8:40 am

Nonstop2h 40m

$157

DenverChicago

DEN - MDW

DENMDW

Denver Intl

mié. 7/9

9:30 pm-12:55 am

Nonstop2h 25m

Chicago Midway

mar. 7/15

5:15 am-6:50 am

Nonstop2h 35m

$163

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

sáb. 8/23

7:02 am-3:42 pm

1 stop7h 40m

Lambert-St Louis

mié. 8/27

9:23 am-3:48 pm

1 stop7h 25m

$187

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

vie. 8/22

12:59 am-8:54 am

1 stop6h 55m

Lambert-St Louis

mié. 8/27

6:00 am-9:55 am

1 stop4h 55m

$207

DenverChicago

DEN - ORD

DENORD

Denver Intl

mié. 8/13

6:20 am-12:45 pm

1 stop5h 25m

Chicago O'Hare Intl

mar. 8/19

8:25 am-12:49 pm

1 stop5h 24m

$217

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/22

Showing 1-10 of 60 results
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Best time to book a flight from Denver to Illinois

Have a flexible travel schedule? Discover the best time to fly to Illinois from Denver with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Denver to Illinois

What is the cheapest month to book a flight from Denver to Illinois?

Currently, August is the cheapest month in which you can book a flight from Denver to Illinois (average of $245). Flying from Denver to Illinois in March is currently the most expensive (average of $321). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from DEN to IL?

Find hourly flight availability from Denver to Illinois. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated mayo 23, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Denver to Illinois as you normally would.

Weekly flight availability from Denver to Illinois

Explore weekly flight availability from Denver to Illinois. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated mayo 23, 2025.

The most flights from DEN to USIL are scheduled on a Thursday (66 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (34 on average).

Rainfall in Illinois by month

Plan your trip to Illinois by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Illinois ranges from 1.7 - 4.9 inches per month. August is typically the wettest month, when rainfall can reach 4.9 in. January is typically the driest time to visit Illinois when rainfall is around 1.7 in.

Temperature in Illinois by month

Plan your trip to Illinois by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Illinois, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 73.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 23.0 F).

Reviews of airlines servicing Illinois

Get insights into the airlines that provide service to Illinois. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Illinois. Reviews last updated mayo 23, 2025.
Get a feel of what it's like to fly with Alaska Airlines, Southwest and Delta from Denver to Illinois by reading reviews from past customers. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.9

Entertainment

7.1

Overall

8.0

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.9

Entertainment

7.1

Overall

8.0

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Southwest
8.0
Very good
4,290 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.9

Entertainment

7.1

Overall

8.0

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Delta
8.0
Very good
7,952 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.9

Entertainment

7.1

Overall

8.0

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
United Airlines
7.4
Good
8,745 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.9

Entertainment

7.1

Overall

8.0

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.
Allegiant Air
7.3
Good
733 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.9

Entertainment

7.1

Overall

8.0

Food

7.1

Boarding

8.2

Crew

8.5

Reviews

1 / 20
10.0
Excellent

James,Apr 2025

LAX - SFO

Good flight except the uncontrollable cold air from the ceiling.

Related info for your journey

Find useful and relevant information for your journey from Denver to Illinois. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Denver to Illinois?

    Most people fly from Denver Intl (DEN) if they book a flight from Denver to Illinois. Denver Intl is conveniently located just 18.5 mi from Denver’s city center.

  • What are the cheapest airlines to fly from Denver to Illinois one-way?

    $53 is the cheapest one-way deal found within the past few days, from Allegiant Air. You may also be able to find cheap deals on Frontier and United Airlines, with prices starting from $78 and $79, respectively.

  • What are the most popular routes from Denver to Illinois?

    When deciding which route to take from Denver to Illinois consider Denver Intl - Chicago O'Hare Intl, Denver Intl - Chicago Midway or Denver Intl - Lambert-St Louis as they are the most popular.

  • What are the most reliable airlines from Denver to Illinois?

    No one likes to see their flight delayed. When booking a flight from Denver to Illinois consider choosing Copa Airlines (94%), Turkish Airlines (92%) or Brussels Airlines (90%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from Denver to Illinois?

    Looking at all options, your cheapest flight can be booked for $78. While the most popular route (Denver Intl - Chicago O'Hare Intl) can be booked for $156 on average our data indicates $1,443 when flying from Denver to Illinois.

  • Can I find deals for flights from Denver to Illinois that include hotel bookings?

    Yes. In addition to deals on Denver to Illinois flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Denver to Illinois?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Denver to Illinois.

  • Can I find deals for business class flights from Denver to Illinois?

    Yes. Cheapflights offers flight deals from Denver to Illinois by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Denver to Illinois?

    Currently, August is the cheapest month in which you can book a flight from Denver to Illinois (average of $245). Flying from Denver to Illinois in March is currently the most expensive (average of $321). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

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Alternative routes for Denver to Illinois

See prices for flight routes from nearby airports that may be better suited for you.
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Denver to Charleston flights

Top 5 airlines flying from Denver to Illinois

Discover the top 5 airlines that operate flights from Denver to Illinois. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated mayo 23, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$54Average$163FlexibilityNo cancel feeOn-time62%
Allegiant AirCheapest$84Average$162FlexibilityNo cancel feeOn-time88%
American AirlinesCheapest$150Average$397FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$155Average$249FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$155Average$360FlexibilityNo cancel feeOn-time69%

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