$65+ 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 7/22. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — DEN
Jul 28 — Aug 41
Round-trip
1 adult, Economy
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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 June 28, 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 June 28, 2026.
This Kiwi.com deal was found by Cheapflights users on 6/27. 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.
Sun 9/2710:07 am
PIA
- DEN
Nonstop2h 20m
Allegiant Air
Sun 9/272:26 pm
DEN
- PIA
Nonstop2h 03m
Allegiant Air
Deal found 6/27![Allegiant Air logo]()
$147
This Cheapflightsfares deal was found by Cheapflights users on 6/27. 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 8/2010:07 am
PIA
- DEN
Nonstop2h 19m
Allegiant Air
Thu 8/272:17 pm
DEN
- PIA
Nonstop2h 07m
Allegiant Air
Deal found 6/27![Allegiant Air logo]()
$151
This Kiwi.com deal was found by Cheapflights users on 6/26. 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.
Sun 8/2310:07 am
PIA
- DEN
Nonstop2h 19m
Allegiant Air
Thu 8/272:17 pm
DEN
- PIA
Nonstop2h 07m
Allegiant Air
Deal found 6/26![Allegiant Air logo]()
$152
This Cheapflightsfares deal was found by Cheapflights users on 6/27. 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.
Sun 9/2710:07 am
PIA
- DEN
Nonstop2h 20m
Allegiant Air
Thu 10/110:20 am
DEN
- PIA
Nonstop1h 59m
Allegiant Air
Deal found 6/27![Allegiant Air logo]()
$156
This Kiwi.com deal was found by Cheapflights users on 6/26. 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 10/138:10 pm
STL
- DEN
Nonstop2h 39m
Frontier
Sat 10/244:12 pm
DEN
- STL
Nonstop2h 03m
Frontier
Deal found 6/26![Frontier logo]()
$162
This Kiwi.com deal was found by Cheapflights users on 6/24. 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.
Sun 8/165:23 pm
PIA
- DEN
Nonstop2h 25m
Allegiant Air
Thu 8/272:17 pm
DEN
- PIA
Nonstop2h 07m
Allegiant Air
Deal found 6/24![Allegiant Air logo]()
$164
This Cheapflightsfares deal was found by Cheapflights users on 6/26. 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.
Tue 7/218:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Tue 7/284:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/26![Frontier logo]()
$164
This Kiwi.com deal was found by Cheapflights users on 6/24. 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 8/48:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Tue 8/114:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/24![Frontier logo]()
$167
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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.
Wed 8/128:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Mon 8/174:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/24![Frontier logo]()
$168
This Kiwi.com deal was found by Cheapflights users on 6/22. 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.
Thu 8/68:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Wed 8/124:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/22![Frontier logo]()
$169
This Frontier deal was found by Cheapflights users on 6/23. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 8/48:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Thu 8/134:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/23![Frontier logo]()
$170
This Frontier deal was found by Cheapflights users on 6/25. 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.
Sat 8/18:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Wed 8/54:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/25![Frontier logo]()
$171
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 June 28, 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 June 28, 2026.
This United Airlines deal was found by Cheapflights users on 6/26. 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 8/175:00 am
ORD
- DEN
Nonstop2h 39m
United Airlines
Tue 8/187:10 pm
DEN
- ORD
Nonstop2h 36m
United Airlines
Deal found 6/26![United Airlines logo]()
$206
This Southwest deal was found by Cheapflights users on 6/26. 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 8/156:00 pm
MDW
- DEN
Nonstop2h 40m
Southwest
Mon 8/176:30 pm
DEN
- MDW
Nonstop2h 30m
Southwest
Deal found 6/26![Southwest logo]()
$206
This Delta deal was found by Cheapflights users on 6/25. 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 10/217:40 pm
ORD
- DEN
1 stop4h 19m
Delta
Sat 10/242:20 pm
DEN
- ORD
1 stop6h 14m
Delta
Deal found 6/25![Delta logo]()
$225
This Sun Country Air deal was found by Cheapflights users on 6/23. 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 Sun Country Air is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/2011:36 am
ORD
- DEN
1 stop8h 03m
Sun Country Air
Mon 11/237:29 pm
DEN
- ORD
1 stop14h 12m
Sun Country Air
Deal found 6/23![Sun Country Air logo]()
$275
This American Airlines deal was found by Cheapflights users on 6/25. 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 10/1711:34 am
CMI
- DEN
1 stop6h 04m
American Airlines
Tue 10/206:30 am
DEN
- CMI
1 stop6h 49m
American Airlines
Deal found 6/25![American Airlines logo]()
$323
This Kiwi.com deal was found by Cheapflights users on 6/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 8/136:39 pm
EVV
- DEN
2 stops28h 03m
Multiple Airlines
Sun 8/167:38 pm
DEN
- EVV
1 stop11h 18m
Multiple Airlines
Deal found 6/23![Multiple Airlines logo]()
$382
This Southwest deal was found by Cheapflights users on 6/23. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 7/155:30 am
MDW
- DEN
Nonstop2h 35m
Southwest
Wed 7/158:10 am
DEN
- MDW
1 stop5h 25m
Southwest
Deal found 6/23![Southwest logo]()
$215
This Delta deal was found by Cheapflights users on 6/23. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/58:00 am
STL
- DEN
1 stop8h 02m
Delta
Wed 8/123:56 pm
DEN
- STL
1 stop7h 45m
Delta
Deal found 6/23![Delta logo]()
$225
This United Airlines deal was found by Cheapflights users on 6/26. 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.
Sun 7/265:00 am
ORD
- DEN
Nonstop2h 41m
United Airlines
Tue 7/289:05 pm
DEN
- ORD
Nonstop2h 39m
United Airlines
Deal found 6/26![United Airlines logo]()
$235
This Southwest deal was found by Cheapflights users on 6/25. 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 7/294:35 pm
MDW
- DEN
1 stop5h 15m
Southwest
Wed 8/51:55 pm
DEN
- MDW
1 stop4h 30m
Southwest
Deal found 6/25![Southwest logo]()
$220
This Delta deal was found by Cheapflights users on 6/24. 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.
Mon 8/107:00 am
ORD
- DEN
1 stop7h 45m
Delta
Sun 8/1612:59 am
DEN
- ORD
1 stop5h 57m
Delta
Deal found 6/24![Delta logo]()
$247
This Southwest deal was found by Cheapflights users on 6/26. 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 8/183:50 pm
MDW
- DEN
Nonstop2h 30m
Southwest
Wed 8/261:40 pm
DEN
- MDW
Nonstop2h 25m
Southwest
Deal found 6/26![Southwest logo]()
$225
This United Airlines deal was found by Cheapflights users on 6/24. 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 9/194:40 pm
STL
- DEN
Nonstop2h 30m
United Airlines
Thu 9/245:30 pm
DEN
- STL
Nonstop2h 06m
United Airlines
Deal found 6/24![United Airlines logo]()
$259
This Delta deal was found by Cheapflights users on 6/22. 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.
Wed 9/27:25 pm
MDW
- DEN
1 stop5h 09m
Delta
Sun 9/610:19 am
DEN
- MDW
1 stop5h 40m
Delta
Deal found 6/22![Delta logo]()
$255
This Southwest deal was found by Cheapflights users on 6/26. 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 8/15:25 am
MDW
- DEN
Nonstop2h 35m
Southwest
Tue 8/47:25 pm
DEN
- MDW
Nonstop2h 25m
Southwest
Deal found 6/26![Southwest logo]()
$236
This American Airlines deal was found by Cheapflights users on 6/27. 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.
Fri 7/176:02 pm
BMI
- DEN
1 stop7h 15m
American Airlines
Tue 7/215:57 pm
DEN
- BMI
1 stop5h 38m
American Airlines
Deal found 6/27![American Airlines logo]()
$324
This United Airlines deal was found by Cheapflights users on 6/22. 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.
Thu 11/58:50 am
PIA
- DEN
Nonstop2h 30m
United Airlines
Tue 11/105:29 pm
DEN
- PIA
Nonstop2h 18m
United Airlines
Deal found 6/22![United Airlines logo]()
$280
This Southwest deal was found by Cheapflights users on 6/22. 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.
Thu 7/235:15 am
MDW
- DEN
Nonstop2h 35m
Southwest
Tue 7/287:40 am
DEN
- MDW
1 stop3h 45m
Southwest
Deal found 6/22![Southwest logo]()
$241
This Delta deal was found by Cheapflights users on 6/25. 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.
Fri 8/2111:22 am
ORD
- DEN
1 stop7h 01m
Delta
Sun 8/2312:59 am
DEN
- ORD
1 stop5h 57m
Delta
Deal found 6/25![Delta logo]()
$266
This American Airlines deal was found by Cheapflights users on 6/25. 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 7/116:34 pm
CMI
- DEN
1 stop6h 43m
American Airlines
Wed 7/156:20 am
DEN
- CMI
1 stop6h 56m
American Airlines
Deal found 6/25![American Airlines logo]()
$342
This United Airlines deal was found by Cheapflights users on 6/26. 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.
Fri 7/109:05 am
MLI
- DEN
Nonstop2h 30m
United Airlines
Fri 7/175:38 pm
DEN
- MLI
Nonstop2h 16m
United Airlines
Deal found 6/26![United Airlines logo]()
$289
This Southwest deal was found by Cheapflights users on 6/23. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/52:15 pm
MDW
- DEN
1 stop5h 15m
Southwest
Mon 9/78:25 pm
DEN
- MDW
Nonstop2h 20m
Southwest
Deal found 6/23![Southwest logo]()
$241
This Delta deal was found by Cheapflights users on 6/26. 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.
Thu 10/87:40 pm
ORD
- DEN
1 stop4h 19m
Delta
Sun 10/1112:55 am
DEN
- ORD
1 stop6h 05m
Delta
Deal found 6/26![Delta logo]()
$266
This American Airlines deal was found by Cheapflights users on 6/27. 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 9/52:47 pm
CMI
- DEN
1 stop5h 51m
American Airlines
Mon 9/75:03 am
DEN
- CMI
1 stop8h 12m
American Airlines
Deal found 6/27![American Airlines logo]()
$345
This Delta deal was found by Cheapflights users on 6/26. 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.
Fri 9/255:10 pm
ORD
- DEN
1 stop5h 23m
Delta
Sun 9/2712:55 am
DEN
- ORD
1 stop6h 02m
Delta
Deal found 6/26![Delta logo]()
$266
This United Airlines deal was found by Cheapflights users on 6/25. 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 8/198:13 am
MLI
- DEN
1 stop7h 18m
United Airlines
Wed 8/265:40 pm
DEN
- MLI
Nonstop2h 21m
United Airlines
Deal found 6/25![United Airlines logo]()
$295
This Southwest deal was found by Cheapflights users on 6/25. 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 9/1212:00 pm
MDW
- DEN
1 stop5h 55m
Southwest
Sun 9/138:00 pm
DEN
- MDW
Nonstop2h 20m
Southwest
Deal found 6/25![Southwest logo]()
$245
This Kiwi.com deal was found by Cheapflights users on 6/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/2011:41 am
EVV
- DEN
2 stops17h 07m
Multiple Airlines
Thu 7/231:05 pm
DEN
- EVV
1 stop20h 46m
Multiple Airlines
Deal found 6/23![Multiple Airlines logo]()
$464
This United Airlines deal was found by Cheapflights users on 6/24. 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 9/224:40 pm
STL
- DEN
Nonstop2h 30m
United Airlines
Wed 9/232:50 pm
DEN
- STL
1 stop7h 09m
United Airlines
Deal found 6/24![United Airlines logo]()
$295
This Southwest deal was found by Cheapflights users on 6/22. 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.
Sun 8/239:30 am
MDW
- DEN
Nonstop2h 35m
Southwest
Thu 8/278:25 pm
DEN
- MDW
Nonstop2h 20m
Southwest
Deal found 6/22![Southwest logo]()
$246
Last-minute flights from Illinois to DenverDiscover last-minute flight deals from Illinois to Denver. Data last updated June 28, 2026 and is based on user searches.
Discover last-minute flight deals from Illinois to Denver. Data last updated June 28, 2026 and is based on user searches.
This Super.com deal was found by Cheapflights users on 6/25. 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.
Wed 7/158:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Wed 7/294:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/25![Frontier logo]()
$168
This Super.com deal was found by Cheapflights users on 6/26. 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.
Wed 7/159:57 pm
ORD
- DEN
Nonstop3h 00m
Frontier
Wed 7/225:05 pm
DEN
- ORD
Nonstop2h 47m
Frontier
Deal found 6/26![Frontier logo]()
$181
This Cheapflightsfares deal was found by Cheapflights users on 6/26. 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.
Wed 7/159:57 pm
ORD
- DEN
Nonstop3h 00m
Frontier
Tue 7/215:05 pm
DEN
- ORD
Nonstop2h 47m
Frontier
Deal found 6/26![Frontier logo]()
$182
This Kiwi.com deal was found by Cheapflights users on 6/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/179:57 pm
ORD
- DEN
Nonstop3h 00m
Frontier
Sat 7/255:05 pm
DEN
- ORD
Nonstop2h 47m
Frontier
Deal found 6/23![Frontier logo]()
$180
This Cheapflightsfares deal was found by Cheapflights users on 6/25. 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 7/189:57 pm
ORD
- DEN
Nonstop3h 00m
Frontier
Mon 8/175:05 pm
DEN
- ORD
Nonstop2h 47m
Frontier
Deal found 6/25![Frontier logo]()
$178
This Kiwi.com deal was found by Cheapflights users on 6/24. 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 7/188:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Tue 7/216:30 am
DEN
- STL
1 stop10h 07m
Frontier
Deal found 6/24![Frontier logo]()
$180
This Kiwi.com deal was found by Cheapflights users on 6/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/189:57 pm
ORD
- DEN
Nonstop3h 00m
Frontier
Wed 7/227:00 am
DEN
- ORD
1 stop16h 49m
Frontier
Deal found 6/23![Frontier logo]()
$184
This Cheapflightsfares deal was found by Cheapflights users on 6/26. 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.
Tue 7/218:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Tue 7/284:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/26![Frontier logo]()
$164
This Kiwi.com deal was found by Cheapflights users on 6/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/219:57 pm
ORD
- DEN
Nonstop3h 00m
Frontier
Wed 7/225:05 pm
DEN
- ORD
Nonstop2h 47m
Frontier
Deal found 6/23![Frontier logo]()
$186
This Cheapflightsfares deal was found by Cheapflights users on 6/27. 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.
Sun 7/269:57 pm
ORD
- DEN
Nonstop3h 00m
Frontier
Fri 7/315:05 pm
DEN
- ORD
Nonstop2h 47m
Frontier
Deal found 6/27![Frontier logo]()
$174
This Kiwi.com deal was found by Cheapflights users on 6/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/314:57 pm
STL
- DEN
1 stop17h 06m
Frontier
Wed 8/54:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/23![Frontier logo]()
$179
This Kiwi.com deal was found by Cheapflights users on 6/23. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 7/314:57 pm
STL
- DEN
1 stop17h 06m
Frontier
Sat 8/14:10 pm
DEN
- STL
Nonstop2h 13m
Frontier
Deal found 6/23![Frontier logo]()
$181
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 June 28, 2026.
Search for one-way flight options from Illinois to Denver. Find affordable one-way fares based on user searches. Data last updated June 28, 2026.
This Kiwi.com deal was found by Cheapflights users on 6/26. 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 7/228:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 6/26![Frontier logo]()
$65
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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.
Sun 8/2310:07 am
PIA
- DEN
Nonstop2h 19m
Allegiant Air
Deal found 6/24![Allegiant Air logo]()
$75
This Cheapflightsfares deal was found by Cheapflights users on 6/24. 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.
Sun 9/2710:07 am
PIA
- DEN
Nonstop2h 20m
Allegiant Air
Deal found 6/24![Allegiant Air logo]()
$81
This Super.com deal was found by Cheapflights users on 6/27. 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.
Sat 7/258:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 6/27![Frontier logo]()
$96
This United Airlines deal was found by Cheapflights users on 6/25. 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 8/254:40 pm
STL
- DEN
Nonstop2h 30m
United Airlines
Deal found 6/25![United Airlines logo]()
$103
This Kiwi.com deal was found by Cheapflights users on 6/24. 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 9/2210:35 am
STL
- DEN
1 stop12h 58m
Frontier
Deal found 6/24![Frontier logo]()
$104
This Cheapflightsfares deal was found by Cheapflights users on 6/26. 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 7/249:57 pm
ORD
- DEN
Nonstop3h 00m
Frontier
Deal found 6/26![Frontier logo]()
$106
This Southwest deal was found by Cheapflights users on 6/23. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 7/2512:50 pm
MDW
- DEN
1 stop4h 45m
Southwest
Deal found 6/23![Southwest logo]()
$108
This Cheapflightsfares deal was found by Cheapflights users on 6/26. 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.
Wed 7/159:57 pm
ORD
- DEN
Nonstop3h 00m
Frontier
Deal found 6/26![Frontier logo]()
$109
This Trip.com deal was found by Cheapflights users on 6/22. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 9/167:25 am
MDW
- DEN
1 stop7h 35m
Frontier
Deal found 6/22![Frontier logo]()
$109
This Kiwi.com deal was found by Cheapflights users on 6/24. 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 8/178:08 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 6/24![Frontier logo]()
$109
This Frontier deal was found by Cheapflights users on 6/25. 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.
Sat 7/189:57 pm
ORD
- DEN
Nonstop3h 00m
Frontier
Deal found 6/25![Frontier logo]()
$111
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 June 28, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $147 (Kiwi.com) |
One-way from | $65 (Kiwi.com) |
Popular in | March |
Cheapest in | October |
Average price | $289 |
Good round-trip deal | $248 or less |
Good one-way deal | $144 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 June 28, 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
Mon 8/17
5:00 am-6:39 am
Nonstop2h 39m
Denver Intl
Tue 8/18
7:10 pm-10:46 pm
Nonstop2h 36m
$206
ChicagoDenver
MDW - DEN
MDWDEN
Chicago Midway
Sat 8/15
6:00 pm-7:40 pm
Nonstop2h 40m
Denver Intl
Mon 8/17
6:30 pm-10:00 pm
Nonstop2h 30m
$206
ChicagoDenver
MDW - DEN
MDWDEN
Chicago Midway
Wed 7/15
5:30 am-7:05 am
Nonstop2h 35m
Denver Intl
Wed 7/15
8:10 am-2:35 pm
1 stop5h 25m
$215
ChicagoDenver
MDW - DEN
MDWDEN
Chicago Midway
Wed 7/29
4:35 pm-8:50 pm
1 stop5h 15m
Denver Intl
Wed 8/5
1:55 pm-7:25 pm
1 stop4h 30m
$220
ChicagoDenver
ORD - DEN
ORDDEN
Chicago O'Hare Intl
Wed 10/21
7:40 pm-10:59 pm
1 stop4h 19m
Denver Intl
Sat 10/24
2:20 pm-9:34 pm
1 stop6h 14m
$225
St. LouisDenver
STL - DEN
STLDEN
Lambert-St Louis
Wed 8/5
8:00 am-3:02 pm
1 stop8h 02m
Denver Intl
Wed 8/12
3:56 pm-12:41 am
1 stop7h 45m
$225
ChicagoDenver
MDW - DEN
MDWDEN
Chicago Midway
Tue 8/18
3:50 pm-5:20 pm
Nonstop2h 30m
Denver Intl
Wed 8/26
1:40 pm-5:05 pm
Nonstop2h 25m
$225
ChicagoDenver
ORD - DEN
ORDDEN
Chicago O'Hare Intl
Sun 7/26
5:00 am-6:41 am
Nonstop2h 41m
Denver Intl
Tue 7/28
9:05 pm-12:44 am
Nonstop2h 39m
$235
ChicagoDenver
MDW - DEN
MDWDEN
Chicago Midway
Sat 8/1
5:25 am-7:00 am
Nonstop2h 35m
Denver Intl
Tue 8/4
7:25 pm-10:50 pm
Nonstop2h 25m
$236
ChicagoDenver
MDW - DEN
MDWDEN
Chicago Midway
Thu 7/23
5:15 am-6:50 am
Nonstop2h 35m
Denver Intl
Tue 7/28
7:40 am-12:25 pm
1 stop3h 45m
$241
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
ORD-DEN
PIA-DEN
MDW-DEN
MLI-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
ORD-DEN
PIA-DEN
MDW-DEN
What is the cheapest month to book a flight from Illinois to Denver?
Currently, November is the cheapest month in which you can book a flight from Illinois to Denver (average of $181). Flying from Illinois to Denver in March is currently the most expensive (average of $350). 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 June 28, 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 27% on your trip compared to booking a flight in the morning.
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 June 28, 2026.
The most flights from USIL to DEN are scheduled on a Saturday (62 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (17 on average).
How much does it cost to fly round-trip from Illinois to Denver?
How far ahead should I book a flight from Illinois to Denver?
To ensure you get the cheapest price possible for a flight from Illinois to Denver, you should look to book at least 84 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.
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 July 20, 2025.
Travelers seeking maximum savings on their Illinois to Denver flight should consider departing on Wednesday afternoons when fares are most often at their lowest. Tuesday at noon flights should be avoided if possible as fares are typically the most expensive at this time.
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
Westminster
Centennial
Lakewood
Broomfield
Golden
Greeley
Lone Tree
Wheat Ridge
Silverthorne
Central City
Fort Morgan
Cripple Creek
Winter Park
Manitou Springs
Frisco
Englewood
Glendale
Evergreen
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.
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Alternative routes for Illinois to Denver
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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 June 28, 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 June 28, 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 7 airlines flying from Illinois to Denver
Discover the top 7 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 June 28, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$51 | Average$244 | FlexibilityNo cancel fee | On-time88% | |
| Cheapest$69 | Average$168 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$105 | Average$284 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$145 | Average$223 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$151 | Average$280 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$154 | Average$369 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$166 | Average$373 | FlexibilityNo cancel fee | On-time69% |