$34+ Cheap flights from Illinois to Denver (DEN)
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 4/8. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — DEN
Apr 19 — Apr 261
Round-trip
1 adult, Economy
We work with more than 300 partners to bring you better travel deals
Find cheap flights from Illinois to Denver with Cheapflights
1. Tell us where you want to go
Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”2. Select your favorite providers
We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.3. Compare prices and book
Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from Illinois to Denver
Cheapest
Best
Last-minute
One-way
Cheapest flights from Illinois to DenverExplore the most affordable flight options available from Illinois to Denver. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 20, 2026.
Explore the most affordable flight options available from Illinois to Denver. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 20, 2026.
This Priceline deal was found by Cheapflights users on 3/20. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/88:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Sat 4/116:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/20![Frontier logo]()
$79
This Cheapflightsfares deal was found by Cheapflights users on 3/15. 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.
Sat 5/28:17 pm
STL
- DEN
Nonstop2h 33m
Frontier
Sat 5/94:15 pm
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/15![Frontier logo]()
$80
This Kiwi.com deal was found by Cheapflights users on 3/17. 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.
Fri 4/38:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Sat 4/116:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/17![Frontier logo]()
$87
This Frontier deal was found by Cheapflights users on 3/17. 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.
Fri 4/38:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Sat 4/46:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/17![Frontier logo]()
$88
This Kiwi.com deal was found by Cheapflights users on 3/17. 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.
Sat 4/48:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Wed 4/86:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/17![Frontier logo]()
$89
This Cheapflightsfares deal was found by Cheapflights users on 3/17. 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.
Fri 4/38:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Fri 4/106:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/17![Frontier logo]()
$94
This Super.com deal was found by Cheapflights users on 3/16. 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.
Fri 4/108:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Mon 4/136:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/16![Frontier logo]()
$99
This Cheapflightsfares deal was found by Cheapflights users on 3/16. 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.
Fri 4/38:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Mon 4/66:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/16![Frontier logo]()
$100
This Frontier deal was found by Cheapflights users on 3/20. 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.
Thu 4/168:06 pm
STL
- DEN
Nonstop2h 33m
Frontier
Wed 5/274:15 pm
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/20![Frontier logo]()
$102
This Frontier deal was found by Cheapflights users on 3/17. 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.
Fri 4/38:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Wed 4/86:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/17![Frontier logo]()
$108
This Kiwi.com deal was found by Cheapflights users on 3/20. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/48:17 pm
STL
- DEN
Nonstop2h 33m
Frontier
Mon 5/114:15 pm
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/20![Frontier logo]()
$111
This Cheapflightsfares deal was found by Cheapflights users on 3/14. 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.
Fri 5/84:28 pm
ORD
- DEN
1 stop7h 35m
Frontier
Mon 5/116:15 am
DEN
- ORD
Nonstop2h 35m
Frontier
Deal found 3/14![Frontier logo]()
$157
Best flights from Illinois to DenverDiscover carefully curated flight deals from Illinois to Denver that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated March 20, 2026.
Discover carefully curated flight deals from Illinois to Denver that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated March 20, 2026.
This Southwest deal was found by Cheapflights users on 3/19. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/2810:30 am
ORD
- DEN
Nonstop2h 45m
Southwest
Tue 5/511:25 am
DEN
- ORD
Nonstop2h 35m
Southwest
Deal found 3/19![Southwest logo]()
$201
This United Airlines deal was found by Cheapflights users on 3/19. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 4/288:11 pm
ORD
- DEN
Nonstop2h 59m
United Airlines
Mon 5/48:20 pm
DEN
- ORD
Nonstop2h 37m
United Airlines
Deal found 3/19![United Airlines logo]()
$211
This Delta deal was found by Cheapflights users on 3/17. 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.
Wed 5/278:05 pm
ORD
- DEN
1 stop4h 36m
Delta
Mon 6/16:05 am
DEN
- ORD
1 stop5h 56m
Delta
Deal found 3/17![Delta logo]()
$231
This American Airlines deal was found by Cheapflights users on 3/17. 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.
Mon 4/136:58 pm
CMI
- DEN
1 stop6h 01m
American Airlines
Tue 4/212:41 pm
DEN
- CMI
1 stop5h 26m
American Airlines
Deal found 3/17![American Airlines logo]()
$278
This Kiwi.com deal was found by Cheapflights users on 3/20. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/177:46 pm
EVV
- DEN
1 stop28h 13m
Multiple Airlines
Fri 4/2411:59 pm
DEN
- EVV
2 stops54h 04m
Multiple Airlines
Deal found 3/20![Multiple Airlines logo]()
$320
This Southwest deal was found by Cheapflights users on 3/17. 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.
Tue 5/125:30 pm
MDW
- DEN
Nonstop2h 40m
Southwest
Sat 5/1611:40 am
DEN
- MDW
1 stop4h 35m
Southwest
Deal found 3/17![Southwest logo]()
$214
This United Airlines deal was found by Cheapflights users on 3/17. 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.
Thu 4/910:04 pm
ORD
- DEN
Nonstop2h 55m
United Airlines
Sat 4/116:00 am
DEN
- ORD
Nonstop2h 37m
United Airlines
Deal found 3/17![United Airlines logo]()
$221
This Southwest deal was found by Cheapflights users on 3/14. 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.
Tue 5/510:30 am
ORD
- DEN
Nonstop2h 45m
Southwest
Tue 5/1211:25 am
DEN
- ORD
Nonstop2h 35m
Southwest
Deal found 3/14![Southwest logo]()
$215
This Delta deal was found by Cheapflights users on 3/17. 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.
Wed 6/37:13 pm
MDW
- DEN
1 stop5h 28m
Delta
Thu 6/412:55 am
DEN
- MDW
1 stop6h 48m
Delta
Deal found 3/17![Delta logo]()
$243
This United Airlines deal was found by Cheapflights users on 3/17. 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.
Mon 4/2011:03 pm
ORD
- DEN
Nonstop2h 55m
United Airlines
Thu 4/238:52 pm
DEN
- ORD
Nonstop2h 38m
United Airlines
Deal found 3/17![United Airlines logo]()
$221
This Southwest deal was found by Cheapflights users on 3/19. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/186:00 am
MDW
- DEN
Nonstop2h 40m
Southwest
Wed 4/2211:45 am
DEN
- MDW
1 stop3h 55m
Southwest
Deal found 3/19![Southwest logo]()
$215
This Delta deal was found by Cheapflights users on 3/19. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 6/69:22 am
MDW
- DEN
1 stop5h 37m
Delta
Mon 6/86:45 am
DEN
- MDW
1 stop4h 45m
Delta
Deal found 3/19![Delta logo]()
$253
This Southwest deal was found by Cheapflights users on 3/17. 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.
Mon 4/279:35 pm
MDW
- DEN
Nonstop2h 40m
Southwest
Wed 4/2911:45 am
DEN
- MDW
1 stop3h 55m
Southwest
Deal found 3/17![Southwest logo]()
$217
This United Airlines deal was found by Cheapflights users on 3/15. 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.
Thu 5/75:59 pm
STL
- DEN
Nonstop2h 34m
United Airlines
Wed 5/135:34 pm
DEN
- STL
Nonstop2h 09m
United Airlines
Deal found 3/15![United Airlines logo]()
$241
This American Airlines deal was found by Cheapflights users on 3/19. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/46:46 am
CMI
- DEN
1 stop8h 11m
American Airlines
Wed 4/81:13 pm
DEN
- CMI
1 stop6h 44m
American Airlines
Deal found 3/19![American Airlines logo]()
$318
This Delta deal was found by Cheapflights users on 3/19. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/65:11 pm
MLI
- DEN
1 stop8h 25m
Delta
Fri 5/81:50 pm
DEN
- MLI
1 stop7h 31m
Delta
Deal found 3/19![Delta logo]()
$267
This Southwest deal was found by Cheapflights users on 3/17. 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.
Mon 4/136:00 am
MDW
- DEN
Nonstop2h 40m
Southwest
Thu 4/168:20 pm
DEN
- MDW
Nonstop2h 20m
Southwest
Deal found 3/17![Southwest logo]()
$221
This United Airlines deal was found by Cheapflights users on 3/18. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/86:05 pm
STL
- DEN
Nonstop2h 34m
United Airlines
Wed 4/151:48 pm
DEN
- STL
Nonstop2h 08m
United Airlines
Deal found 3/18![United Airlines logo]()
$271
This Southwest deal was found by Cheapflights users on 3/16. 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.
Sat 5/93:05 pm
ORD
- DEN
Nonstop3h 00m
Southwest
Sun 5/1011:25 am
DEN
- ORD
Nonstop2h 35m
Southwest
Deal found 3/16![Southwest logo]()
$230
This Delta deal was found by Cheapflights users on 3/17. 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.
Sat 4/1812:02 pm
BMI
- DEN
1 stop6h 23m
Delta
Sat 4/253:30 pm
DEN
- BMI
1 stop5h 51m
Delta
Deal found 3/17![Delta logo]()
$289
This American Airlines deal was found by Cheapflights users on 3/19. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/136:58 pm
CMI
- DEN
1 stop6h 01m
American Airlines
Fri 4/175:30 am
DEN
- CMI
1 stop8h 09m
American Airlines
Deal found 3/19![American Airlines logo]()
$356
This United Airlines deal was found by Cheapflights users on 3/15. 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.
Sat 5/29:49 am
CMI
- DEN
1 stop6h 50m
United Airlines
Sat 5/164:45 pm
DEN
- CMI
1 stop4h 48m
United Airlines
Deal found 3/15![United Airlines logo]()
$278
This Southwest deal was found by Cheapflights users on 3/18. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/158:25 am
STL
- DEN
1 stop6h 10m
Southwest
Sat 4/187:15 am
DEN
- STL
2 stops7h 05m
Southwest
Deal found 3/18![Southwest logo]()
$230
This Kiwi.com deal was found by Cheapflights users on 3/16. 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.
Thu 5/288:08 am
EVV
- DEN
2 stops31h 24m
Multiple Airlines
Sun 5/311:22 pm
DEN
- EVV
1 stop17h 17m
Multiple Airlines
Deal found 3/16![Multiple Airlines logo]()
$431
This American Airlines deal was found by Cheapflights users on 3/18. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/136:55 pm
CMI
- DEN
1 stop4h 50m
American Airlines
Thu 5/282:21 pm
DEN
- CMI
1 stop5h 47m
American Airlines
Deal found 3/18![American Airlines logo]()
$368
This Southwest deal was found by Cheapflights users on 3/17. 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.
Sat 5/91:55 pm
MDW
- DEN
Nonstop2h 40m
Southwest
Sun 5/107:50 am
DEN
- MDW
Nonstop2h 25m
Southwest
Deal found 3/17![Southwest logo]()
$230
This United Airlines deal was found by Cheapflights users on 3/18. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 5/76:51 pm
BMI
- DEN
1 stop5h 59m
United Airlines
Sun 5/106:00 am
DEN
- BMI
1 stop5h 51m
United Airlines
Deal found 3/18![United Airlines logo]()
$289
This Southwest deal was found by Cheapflights users on 3/19. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/169:40 pm
STL
- DEN
Nonstop2h 20m
Southwest
Thu 4/236:00 am
DEN
- STL
1 stop5h 30m
Southwest
Deal found 3/19![Southwest logo]()
$231
This Kiwi.com deal was found by Cheapflights users on 3/15. 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.
Mon 3/307:46 pm
EVV
- DEN
2 stops37h 56m
Multiple Airlines
Fri 4/39:25 am
DEN
- EVV
1 stop8h 41m
Multiple Airlines
Deal found 3/15![Multiple Airlines logo]()
$452
This Delta deal was found by Cheapflights users on 3/19. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 4/114:04 pm
BMI
- DEN
1 stop9h 05m
Delta
Wed 4/151:25 pm
DEN
- BMI
1 stop7h 56m
Delta
Deal found 3/19![Delta logo]()
$344
Last-minute flights from Illinois to DenverDiscover last-minute flight deals from Illinois to Denver. Data last updated March 20, 2026 and is based on user searches.
Discover last-minute flight deals from Illinois to Denver. Data last updated March 20, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 3/17. 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.
Fri 4/38:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Sat 4/116:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/17![Frontier logo]()
$87
This Frontier deal was found by Cheapflights users on 3/17. 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.
Fri 4/38:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Sat 4/46:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/17![Frontier logo]()
$88
This Cheapflightsfares deal was found by Cheapflights users on 3/17. 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.
Fri 4/38:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Fri 4/106:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/17![Frontier logo]()
$94
This Cheapflightsfares deal was found by Cheapflights users on 3/16. 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.
Fri 4/38:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Mon 4/66:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/16![Frontier logo]()
$100
This Frontier deal was found by Cheapflights users on 3/17. 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.
Fri 4/38:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Wed 4/86:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/17![Frontier logo]()
$108
This Kiwi.com deal was found by Cheapflights users on 3/17. 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.
Sat 4/48:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Wed 4/86:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/17![Frontier logo]()
$89
This Priceline deal was found by Cheapflights users on 3/20. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/88:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Sat 4/116:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/20![Frontier logo]()
$79
This Super.com deal was found by Cheapflights users on 3/16. 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.
Fri 4/108:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Mon 4/136:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/16![Frontier logo]()
$99
This Frontier deal was found by Cheapflights users on 3/20. 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.
Thu 4/168:06 pm
STL
- DEN
Nonstop2h 33m
Frontier
Wed 5/274:15 pm
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 3/20![Frontier logo]()
$102
This Cheapflightsfares deal was found by Cheapflights users on 3/19. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/168:06 pm
STL
- DEN
Nonstop2h 33m
Frontier
Thu 4/234:09 pm
DEN
- STL
Nonstop2h 12m
Frontier
Deal found 3/19![Frontier logo]()
$111
This Frontier deal was found by Cheapflights users on 3/15. 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.
Fri 4/1710:55 am
ORD
- DEN
Nonstop3h 03m
Frontier
Sat 4/181:09 pm
DEN
- ORD
1 stop8h 30m
Frontier
Deal found 3/15![Frontier logo]()
$157
This Frontier deal was found by Cheapflights users on 3/19. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/209:55 pm
STL
- DEN
1 stop7h 04m
Frontier
Sat 4/254:20 pm
DEN
- STL
Nonstop2h 12m
Frontier
Deal found 3/19![Frontier logo]()
$114
One-way flights from Illinois to DenverSearch for one-way flight options from Illinois to Denver. Find affordable one-way fares based on user searches. Data last updated March 20, 2026.
Search for one-way flight options from Illinois to Denver. Find affordable one-way fares based on user searches. Data last updated March 20, 2026.
This Kiwi.com deal was found by Cheapflights users on 3/18. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/88:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Deal found 3/18![Frontier logo]()
$34
This Kiwi.com deal was found by Cheapflights users on 3/18. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/38:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Deal found 3/18![Frontier logo]()
$43
This Frontier deal was found by Cheapflights users on 3/19. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/178:06 pm
STL
- DEN
Nonstop2h 33m
Frontier
Deal found 3/19![Frontier logo]()
$44
This Frontier deal was found by Cheapflights users on 3/19. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/168:06 pm
STL
- DEN
Nonstop2h 33m
Frontier
Deal found 3/19![Frontier logo]()
$56
This Super.com deal was found by Cheapflights users on 3/16. 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.
Mon 4/68:19 pm
STL
- DEN
Nonstop2h 33m
Frontier
Deal found 3/16![Frontier logo]()
$65
This Frontier deal was found by Cheapflights users on 3/19. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/209:55 pm
STL
- DEN
1 stop7h 04m
Frontier
Deal found 3/19![Frontier logo]()
$70
This Frontier deal was found by Cheapflights users on 3/18. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/158:08 pm
STL
- DEN
Nonstop2h 33m
Frontier
Deal found 3/18![Frontier logo]()
$74
This Kiwi.com deal was found by Cheapflights users on 3/17. 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.
Tue 4/711:21 am
STL
- DEN
1 stop12h 43m
Frontier
Deal found 3/17![Frontier logo]()
$88
This Kiwi.com deal was found by Cheapflights users on 3/16. 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.
Tue 4/143:27 pm
ORD
- DEN
1 stop18h 23m
Frontier
Deal found 3/16![Frontier logo]()
$88
This Kiwi.com deal was found by Cheapflights users on 3/15. 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.
Tue 5/123:07 pm
MDW
- DEN
1 stop20h 28m
Frontier
Deal found 3/15![Frontier logo]()
$88
This Super.com deal was found by Cheapflights users on 3/17. 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.
Thu 4/96:00 pm
ORD
- DEN
1 stop6h 58m
Frontier
Deal found 3/17![Frontier logo]()
$89
This Super.com deal was found by Cheapflights users on 3/17. 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.
Thu 4/306:00 am
MDW
- DEN
1 stop7h 14m
Frontier
Deal found 3/17![Frontier logo]()
$89
Find flight deals from Illinois to Denver
Keep the following information in mind while searching for Illinois to Denver flight deals. Data was last updated March 20, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $79 (Priceline) |
One-way from | $34 (Kiwi.com) |
Popular in | March |
Cheapest in | October |
Average price | $274 |
Good round-trip deal | $224 or less |
Good one-way deal | $137 or less |
Cheapflights 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, Cheapflights users made 2,558,603 searches. Data last updated March 20, 2026.
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
Cheapest round-trip
ChicagoDenver
ORD - DEN
ORDDEN
Chicago O'Hare Intl
Tue 4/28
10:30 am-12:15 pm
Nonstop2h 45m
Denver Intl
Tue 5/5
11:25 am-3:00 pm
Nonstop2h 35m
$201
ChicagoDenver
ORD - DEN
ORDDEN
Chicago O'Hare Intl
Tue 4/28
8:11 pm-10:10 pm
Nonstop2h 59m
Denver Intl
Mon 5/4
8:20 pm-11:57 pm
Nonstop2h 37m
$211
ChicagoDenver
MDW - DEN
MDWDEN
Chicago Midway
Tue 5/12
5:30 pm-7:10 pm
Nonstop2h 40m
Denver Intl
Sat 5/16
11:40 am-5:15 pm
1 stop4h 35m
$214
ChicagoDenver
ORD - DEN
ORDDEN
Chicago O'Hare Intl
Tue 5/5
10:30 am-12:15 pm
Nonstop2h 45m
Denver Intl
Tue 5/12
11:25 am-3:00 pm
Nonstop2h 35m
$215
ChicagoDenver
MDW - DEN
MDWDEN
Chicago Midway
Sat 4/18
6:00 am-7:40 am
Nonstop2h 40m
Denver Intl
Wed 4/22
11:45 am-4:40 pm
1 stop3h 55m
$215
ChicagoDenver
MDW - DEN
MDWDEN
Chicago Midway
Mon 4/27
9:35 pm-11:15 pm
Nonstop2h 40m
Denver Intl
Wed 4/29
11:45 am-4:40 pm
1 stop3h 55m
$217
ChicagoDenver
ORD - DEN
ORDDEN
Chicago O'Hare Intl
Thu 4/9
10:04 pm-11:59 pm
Nonstop2h 55m
Denver Intl
Sat 4/11
6:00 am-9:37 am
Nonstop2h 37m
$221
ChicagoDenver
ORD - DEN
ORDDEN
Chicago O'Hare Intl
Mon 4/20
11:03 pm-12:58 am
Nonstop2h 55m
Denver Intl
Thu 4/23
8:52 pm-12:30 am
Nonstop2h 38m
$221
ChicagoDenver
MDW - DEN
MDWDEN
Chicago Midway
Mon 4/13
6:00 am-7:40 am
Nonstop2h 40m
Denver Intl
Thu 4/16
8:20 pm-11:40 pm
Nonstop2h 20m
$221
ChicagoDenver
ORD - DEN
ORDDEN
Chicago O'Hare Intl
Sat 5/9
3:05 pm-5:05 pm
Nonstop3h 00m
Denver Intl
Sun 5/10
11:25 am-3:00 pm
Nonstop2h 35m
$230
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Illinois to Denver
Have a flexible travel schedule? Discover the best time to fly to Denver from Illinois with our price prediction graph.
STL-DEN
MDW-DEN
ORD-DEN
EVV-DEN
PIA-DEN
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 Illinois to Denver
USIL-DEN
STL-DEN
MDW-DEN
ORD-DEN
EVV-DEN
What is the cheapest month to book a flight from Illinois to Denver?
Currently, September is the cheapest month in which you can book a flight from Illinois to Denver (average of $48). Flying from Illinois to Denver in February is currently the most expensive (average of $113). 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 IL to DEN?
Find hourly flight availability from Illinois to Denver. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated March 20, 2026.
A simple way to save on the total cost of your ticket is to fly from Illinois to Denver in the evening. If you’re flexible enough to do this you can expect to save up to 33% on your trip compared to booking a flight in the morning.
What is the cheapest day to fly from Illinois to Denver?
Use this chart to determine the cheapest time to fly round-trip from Illinois to Denver. Price data was last updated on March 30, 2025.
Travelers seeking maximum savings on their Illinois to Denver flight should consider departing on Saturday afternoons when fares are most often at their lowest. Sunday mornings flights should be avoided if possible as fares are typically the most expensive at this time.
Weekly flight availability from Illinois to Denver
Explore weekly flight availability from Illinois to Denver. 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 March 20, 2026.
The most flights from USIL to DEN are scheduled on a Friday (54 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (31 on average).
How much does it cost to fly round-trip from Illinois to Denver?
Related info for your journey
Find useful and relevant information for your journey from Illinois to Denver. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Traveling to a place near Denver?
Book flights to Denver if you plan to visit one of these locationsThornton
Black Hawk
Lakewood
Broomfield
Westminster
Golden
Centennial
Greeley
Lone Tree
Wheat Ridge
Silverthorne
Central City
Cripple Creek
Winter Park
Glendale
Manitou Springs
Frisco
Englewood
Fort Morgan
Brighton
Browse thousands of different options on Cheapflights for your next trip
Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.
Alternative routes
Complete your trip
Denver flight routes
Flights by cabin class
Other flight options
Popular flights
Top destinations
Alternative routes for Illinois to Denver
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Denver by adding a car rental and/or hotel reservation to your travel itinerary.
Other flights to Denver
Explore flights to Denver departing from other origins. Flights are based on user searches made on Cheapflights and were last updated on March 20, 2026.
Search flights from Illinois to Denver by cabin class
Find flights from Illinois to Denver, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Illinois and Denver flights
Browse other Illinois and Denver flight options. Last updated on March 20, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Illinois to Denver flights
Consider these flights traveling from Illinois to Denver.
Top 6 airlines flying from Illinois to Denver
Discover the top 6 airlines that operate flights from Illinois to Denver. 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 March 20, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$55 | Average$146 | FlexibilityNo cancel fee | On-time88% | |
| Cheapest$68 | Average$167 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$145 | Average$223 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$151 | Average$370 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$157 | Average$357 | FlexibilityNo cancel fee | On-time69% | |
| Cheapest$157 | Average$254 | FlexibilityNo cancel fee | On-time63% |