$43+ 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 2/18. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — ORD
févr. 20 — févr. 271
1 adult, Economy
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Cheapest flights from Denver to IllinoisExplore 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 janvier 21, 2026.
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 janvier 21, 2026.
This Kiwi.com deal was found by Cheapflights users on 1/21. 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.
mer. 2/411:38 am
DEN
- STL
Nonstop2h 08m
Frontier
sam. 2/73:46 pm
STL
- DEN
Nonstop2h 37m
Frontier
Deal found 1/21![Frontier logo]()
$82
This Frontier deal was found by Cheapflights users on 1/21. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mer. 2/411:38 am
DEN
- STL
Nonstop2h 08m
Frontier
mer. 2/113:28 pm
STL
- DEN
Nonstop2h 37m
Frontier
Deal found 1/21![Frontier logo]()
$83
This Cheapflightsfares deal was found by Cheapflights users on 1/18. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
ven. 2/2710:01 am
DEN
- STL
Nonstop2h 08m
Frontier
lun. 3/21:54 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 1/18![Frontier logo]()
$88
This CheapOair deal was found by Cheapflights users on 1/21. 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.
sam. 2/2110:48 am
DEN
- STL
Nonstop2h 08m
Frontier
mer. 2/253:49 pm
STL
- DEN
1 stop17h 06m
Frontier
Deal found 1/21![Frontier logo]()
$92
This Super.com deal was found by Cheapflights users on 1/20. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
ven. 1/303:38 pm
DEN
- STL
Nonstop2h 06m
Frontier
lun. 2/21:40 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 1/20![Frontier logo]()
$97
This Frontier deal was found by Cheapflights users on 1/20. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
ven. 2/63:38 pm
DEN
- STL
Nonstop2h 06m
Frontier
lun. 2/91:40 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 1/20![Frontier logo]()
$98
This Super.com deal was found by Cheapflights users on 1/20. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
ven. 1/303:38 pm
DEN
- STL
Nonstop2h 06m
Frontier
dim. 2/112:03 pm
STL
- DEN
Nonstop2h 33m
Frontier
Deal found 1/20![Frontier logo]()
$102
This deal was found by Cheapflights users on 1/21. 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 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
ven. 2/63:38 pm
DEN
- STL
Nonstop2h 06m
Frontier
dim. 2/812:03 pm
STL
- DEN
Nonstop2h 33m
Frontier
Deal found 1/21![Frontier logo]()
$103
This Kiwi.com deal was found by Cheapflights users on 1/21. 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.
sam. 2/711:38 am
DEN
- STL
Nonstop2h 08m
Frontier
lun. 2/98:22 pm
STL
- DEN
1 stop16h 47m
Frontier
Deal found 1/21![Frontier logo]()
$105
This Cheapflightsfares deal was found by Cheapflights users on 1/18. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jeu. 2/196:15 pm
DEN
- STL
1 stop26h 11m
Frontier
sam. 2/212:51 pm
STL
- DEN
Nonstop2h 27m
Frontier
Deal found 1/18![Frontier logo]()
$107
This Super.com deal was found by Cheapflights users on 1/19. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
ven. 2/208:24 am
DEN
- ORD
Nonstop2h 34m
Frontier
sam. 2/211:37 pm
ORD
- DEN
1 stop9h 12m
Frontier
Deal found 1/19![Frontier logo]()
$108
This Cheapflightsfares deal was found by Cheapflights users on 1/18. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sam. 2/2110:48 am
DEN
- STL
Nonstop2h 08m
Frontier
lun. 2/231:54 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 1/18![Frontier logo]()
$108
Find flight deals from Denver to Illinois
Keep the following information in mind while searching for Denver to Illinois flight deals. Data was last updated janvier 21, 2026.
Most accurate provider | CheapOair 3 stars |
|---|---|
Most trusted provider | CheapOair 3 stars |
Round-trip from | $82 (Kiwi.com) |
One-way from | $43 (Kiwi.com) |
Popular in | November |
Cheapest in | February |
Average price | $208 |
Good round-trip deal | $213 or less |
Good one-way deal | $126 or less |
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 janvier 21, 2026.
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
DenverChicago
DEN - MDW
DENMDW
Denver Intl
mer. 3/4
4:35 pm-7:55 pm
Nonstop2h 20m
Chicago Midway
jeu. 3/12
9:40 pm-11:20 pm
Nonstop2h 40m
$167
DenverChicago
DEN - MDW
DENMDW
Denver Intl
mer. 3/4
8:45 am-4:35 pm
1 stop6h 50m
Chicago Midway
jeu. 3/5
5:40 am-7:25 am
Nonstop2h 45m
$177
DenverSt. Louis
DEN - STL
DENSTL
Denver Intl
jeu. 2/19
12:42 pm-6:51 am
2 stops17h 09m
Lambert-St Louis
sam. 2/21
8:17 pm-9:16 am
1 stop13h 59m
$185
DenverChicago
DEN - MDW
DENMDW
Denver Intl
mer. 4/1
6:10 pm-12:05 am
1 stop4h 55m
Chicago Midway
sam. 4/4
6:50 pm-12:20 am
1 stop6h 30m
$187
DenverSt. Louis
DEN - STL
DENSTL
Denver Intl
mer. 2/4
11:38 am-2:46 pm
Nonstop2h 08m
Lambert-St Louis
dim. 2/8
1:03 pm-11:20 am
1 stop23h 17m
$192
DenverChicago
DEN - ORD
DENORD
Denver Intl
ven. 3/6
11:30 am-3:05 pm
Nonstop2h 35m
Chicago O'Hare Intl
lun. 3/9
6:25 pm-8:15 pm
Nonstop2h 50m
$194
DenverChicago
DEN - MDW
DENMDW
Denver Intl
mer. 4/1
6:20 am-1:25 pm
1 stop6h 05m
Chicago Midway
sam. 4/4
2:05 pm-7:51 pm
1 stop6h 46m
$197
DenverChicago
DEN - MDW
DENMDW
Denver Intl
jeu. 3/12
6:20 am-9:45 am
Nonstop2h 25m
Chicago Midway
dim. 3/15
5:55 am-7:40 am
Nonstop2h 45m
$200
DenverChicago
DEN - MDW
DENMDW
Denver Intl
sam. 2/28
7:20 am-10:55 am
Nonstop2h 35m
Chicago Midway
lun. 3/2
7:55 am-12:10 pm
1 stop5h 15m
$201
DenverChicago
DEN - ORD
DENORD
Denver Intl
ven. 4/10
6:10 am-1:17 pm
1 stop6h 07m
Chicago O'Hare Intl
mar. 4/14
8:15 am-3:20 pm
1 stop8h 05m
$204
Showing 1-10 of 60 results
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, July is the cheapest month in which you can book a flight from Denver to Illinois (average of $46). Flying from Denver to Illinois in June is currently the most expensive (average of $109). 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 janvier 21, 2026.
It’s optimal to fly from Denver to Illinois in the morning. By choosing this option you can save up to 28% on the cost of your flight, compared to a flight at noon.
What is the cheapest day to fly from Denver to Illinois?
Use this chart to determine the cheapest time to fly round-trip from Denver to Illinois. Price data was last updated on May 11, 2025.
Travelers seeking maximum savings on their Denver to Illinois flight should consider departing on Friday at noon when fares are most often at their lowest. Wednesday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
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 janvier 21, 2026.
The most flights from DEN to USIL are scheduled on a Monday (45 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (25 on average).
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 janvier 21, 2026.
Read through reviews of airlines operating flights from Denver to Illinois, such as Southwest, United Airlines, and American Airlines. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Crew
8.6
Food
7.0
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Food
7.0
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Food
7.0
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Food
7.0
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Food
7.0
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Crew
8.6
Food
7.0
Overall
8.0
Boarding
8.1
Comfort
8.0
Entertainment
7.5
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
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.
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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.
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 janvier 21, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$61 | Average$171 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$68 | Average$136 | FlexibilityNo cancel fee | On-time88% | |
| Cheapest$155 | Average$261 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$156 | Average$340 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$157 | Average$413 | FlexibilityNo cancel fee | On-time71% |