$40+ 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 3/13. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — ORD
Mar 5 — Mar 121
1 adult, Economy
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Find cheap flights from Denver to Illinois with Cheapflights
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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 February 3, 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 February 3, 2026.
This Super.com deal was found by Cheapflights users on 2/1. 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 2/2512:48 pm
DEN
- STL
Nonstop2h 05m
Frontier
Sat 2/282:51 pm
STL
- DEN
Nonstop2h 27m
Frontier
Deal found 2/1![Frontier logo]()
$79
This Frontier deal was found by Cheapflights users on 2/1. 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 2/2010:01 am
DEN
- STL
Nonstop2h 08m
Frontier
Wed 2/254:51 pm
STL
- DEN
Nonstop2h 34m
Frontier
Deal found 2/1![Frontier logo]()
$80
This Kiwi.com deal was found by Cheapflights users on 2/1. 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 3/212:59 am
DEN
- STL
1 stop28h 52m
Frontier
Sat 3/78:12 pm
STL
- DEN
Nonstop2h 37m
Frontier
Deal found 2/1![Frontier logo]()
$84
This Super.com deal was found by Cheapflights users on 1/31. 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 3/276:35 am
DEN
- STL
Nonstop2h 14m
Frontier
Mon 3/308:12 pm
STL
- DEN
Nonstop2h 37m
Frontier
Deal found 1/31![Frontier logo]()
$88
This Expedia deal was found by Cheapflights users on 2/1. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/286:35 am
DEN
- STL
Nonstop2h 14m
Frontier
Sat 4/48:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Deal found 2/1![Frontier logo]()
$93
This Kiwi.com deal was found by Cheapflights users on 2/2. 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 3/412:48 pm
DEN
- STL
Nonstop2h 05m
Frontier
Wed 3/1111:32 am
STL
- DEN
1 stop12h 32m
Frontier
Deal found 2/2![Frontier logo]()
$106
This Expedia deal was found by Cheapflights users on 2/1. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/2110:48 am
DEN
- STL
Nonstop2h 08m
Frontier
Mon 2/238:47 pm
STL
- DEN
1 stop12h 07m
Frontier
Deal found 2/1![Frontier logo]()
$107
This Mytrip deal was found by Cheapflights users on 2/1. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/2411:59 pm
DEN
- STL
1 stop21h 28m
Frontier
Fri 2/271:59 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 2/1![Frontier logo]()
$110
This Frontier deal was found by Cheapflights users on 1/31. 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.
Wed 2/1812:48 pm
DEN
- STL
Nonstop2h 05m
Frontier
Sat 2/212:51 pm
STL
- DEN
Nonstop2h 27m
Frontier
Deal found 1/31![Frontier logo]()
$111
This Cheapflightsfares deal was found by Cheapflights users on 2/2. 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 2/2010:01 am
DEN
- STL
Nonstop2h 08m
Frontier
Thu 2/2610:11 pm
STL
- DEN
1 stop21h 09m
Frontier
Deal found 2/2![Frontier logo]()
$113
This Cheapflightsfares deal was found by Cheapflights users on 2/2. 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 4/236:15 am
DEN
- ORD
Nonstop2h 35m
Frontier
Mon 4/277:21 pm
ORD
- DEN
1 stop16h 26m
Frontier
Deal found 2/2![Frontier logo]()
$120
This Frontier deal was found by Cheapflights users on 2/1. 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.
Wed 4/221:09 pm
DEN
- ORD
1 stop8h 30m
Frontier
Mon 4/2710:55 am
ORD
- DEN
Nonstop3h 03m
Frontier
Deal found 2/1![Frontier logo]()
$121
Best flights from Denver to IllinoisDiscover carefully curated flight deals from Denver to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 3, 2026.
Discover carefully curated flight deals from Denver to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated February 3, 2026.
This Frontier deal was found by Cheapflights users on 2/2. 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 3/236:35 am
DEN
- STL
Nonstop2h 14m
Frontier
Fri 3/278:12 pm
STL
- DEN
Nonstop2h 37m
Frontier
Deal found 2/2![Frontier logo]()
$114
This United Airlines deal was found by Cheapflights users on 2/1. 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 3/38:30 pm
DEN
- ORD
Nonstop2h 29m
United Airlines
Tue 3/108:40 am
ORD
- DEN
Nonstop2h 53m
United Airlines
Deal found 2/1![United Airlines logo]()
$185
This Southwest deal was found by Cheapflights users on 1/31. 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 4/238:20 pm
DEN
- MDW
Nonstop2h 20m
Southwest
Sat 4/253:00 pm
MDW
- DEN
1 stop5h 00m
Southwest
Deal found 1/31![Southwest logo]()
$185
This Delta deal was found by Cheapflights users on 2/2. 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 4/912:35 am
DEN
- ORD
1 stop7h 35m
Delta
Mon 4/137:09 pm
ORD
- DEN
1 stop5h 06m
Delta
Deal found 2/2![Delta logo]()
$211
This American Airlines deal was found by Cheapflights users on 2/2. 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 4/175:44 pm
DEN
- BMI
1 stop5h 08m
American Airlines
Sat 4/183:45 pm
BMI
- DEN
1 stop7h 14m
American Airlines
Deal found 2/2![American Airlines logo]()
$229
This Kiwi.com deal was found by Cheapflights users on 2/2. 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 2/1611:25 pm
DEN
- STL
2 stops30h 26m
Multiple Airlines
Fri 2/208:20 pm
STL
- DEN
1 stop17h 18m
Multiple Airlines
Deal found 2/2![Multiple Airlines logo]()
$232
This United Airlines deal was found by Cheapflights users on 2/2. 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 5/123:20 pm
DEN
- ORD
Nonstop2h 39m
United Airlines
Tue 5/192:20 pm
ORD
- DEN
Nonstop2h 56m
United Airlines
Deal found 2/2![United Airlines logo]()
$185
This Southwest deal was found by Cheapflights users on 2/1. 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.
Fri 4/36:20 am
DEN
- MDW
Nonstop2h 25m
Southwest
Mon 4/69:40 pm
MDW
- DEN
Nonstop2h 40m
Southwest
Deal found 2/1![Southwest logo]()
$191
This Orbitz deal was found by Cheapflights users on 2/2. 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 Orbitz is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/156:30 am
DEN
- MDW
1 stop7h 19m
Frontier
Mon 5/186:15 am
MDW
- DEN
1 stop6h 36m
Frontier
Deal found 2/2![Frontier logo]()
$195
This Delta deal was found by Cheapflights users on 1/31. 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 4/2212:35 am
DEN
- ORD
1 stop6h 05m
Delta
Mon 4/277:09 pm
ORD
- DEN
1 stop5h 06m
Delta
Deal found 1/31![Delta logo]()
$211
This United Airlines deal was found by Cheapflights users on 1/31. 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 2/216:00 am
DEN
- ORD
Nonstop2h 38m
United Airlines
Sun 2/228:07 pm
ORD
- DEN
Nonstop2h 58m
United Airlines
Deal found 1/31![United Airlines logo]()
$193
This Southwest deal was found by Cheapflights users on 2/2. 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 3/510:25 am
DEN
- MDW
Nonstop2h 25m
Southwest
Mon 3/95:40 pm
MDW
- DEN
Nonstop2h 40m
Southwest
Deal found 2/2![Southwest logo]()
$194
This Cheapflightsfares deal was found by Cheapflights users on 2/2. 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 3/57:24 pm
DEN
- STL
1 stop10h 38m
Frontier
Sat 3/77:47 am
STL
- DEN
1 stop15h 37m
Frontier
Deal found 2/2![Frontier logo]()
$197
This Delta deal was found by Cheapflights users on 2/1. 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 3/306:10 am
DEN
- ORD
1 stop6h 07m
Delta
Mon 4/65:59 pm
ORD
- DEN
1 stop7h 10m
Delta
Deal found 2/1![Delta logo]()
$211
This Southwest deal was found by Cheapflights users on 2/2. 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 4/308:20 pm
DEN
- MDW
Nonstop2h 20m
Southwest
Sat 5/26:00 am
MDW
- DEN
Nonstop2h 40m
Southwest
Deal found 2/2![Southwest logo]()
$195
This American Airlines deal was found by Cheapflights users on 2/1. 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 2/218:00 am
DEN
- BMI
1 stop5h 33m
American Airlines
Mon 2/232:56 pm
BMI
- DEN
1 stop6h 54m
American Airlines
Deal found 2/1![American Airlines logo]()
$249
This United Airlines deal was found by Cheapflights users on 2/2. 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 4/27:50 pm
DEN
- ORD
Nonstop2h 38m
United Airlines
Sun 4/57:00 am
ORD
- DEN
Nonstop2h 55m
United Airlines
Deal found 2/2![United Airlines logo]()
$208
This Southwest deal was found by Cheapflights users on 2/2. 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 3/75:55 am
DEN
- MDW
Nonstop2h 25m
Southwest
Sun 3/810:05 pm
MDW
- DEN
Nonstop2h 40m
Southwest
Deal found 2/2![Southwest logo]()
$197
This American Airlines deal was found by Cheapflights users on 2/2. 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 2/189:10 am
DEN
- BMI
1 stop5h 05m
American Airlines
Mon 2/235:00 am
BMI
- DEN
1 stop4h 47m
American Airlines
Deal found 2/2![American Airlines logo]()
$249
This Delta deal was found by Cheapflights users on 2/1. 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 3/57:20 am
DEN
- MLI
1 stop7h 56m
Delta
Sat 3/75:01 pm
MLI
- DEN
1 stop8h 22m
Delta
Deal found 2/1![Delta logo]()
$229
This Southwest deal was found by Cheapflights users on 2/2. 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 4/213:50 pm
DEN
- MDW
1 stop4h 55m
Southwest
Thu 4/239:35 pm
MDW
- DEN
Nonstop2h 40m
Southwest
Deal found 2/2![Southwest logo]()
$198
This United Airlines deal was found by Cheapflights users on 2/2. 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 3/45:37 pm
DEN
- MLI
Nonstop2h 17m
United Airlines
Sun 3/87:22 pm
MLI
- DEN
1 stop5h 08m
United Airlines
Deal found 2/2![United Airlines logo]()
$219
This American Airlines deal was found by Cheapflights users on 2/1. 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 2/205:57 pm
DEN
- PIA
1 stop4h 28m
American Airlines
Fri 2/277:00 pm
PIA
- DEN
1 stop4h 37m
American Airlines
Deal found 2/1![American Airlines logo]()
$249
This United Airlines deal was found by Cheapflights users on 2/1. 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 2/255:37 pm
DEN
- MLI
Nonstop2h 17m
United Airlines
Sun 3/87:22 pm
MLI
- DEN
1 stop5h 08m
United Airlines
Deal found 2/1![United Airlines logo]()
$219
This Southwest deal was found by Cheapflights users on 2/1. 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 4/118:20 am
DEN
- ORD
1 stop6h 10m
Southwest
Mon 4/133:45 pm
ORD
- DEN
2 stops8h 00m
Southwest
Deal found 2/1![Southwest logo]()
$200
This Kiwi.com deal was found by Cheapflights users on 2/2. 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 4/162:02 pm
DEN
- STL
2 stops15h 48m
Frontier
Sun 4/199:55 pm
STL
- DEN
1 stop7h 04m
Frontier
Deal found 2/2![Frontier logo]()
$278
This Southwest deal was found by Cheapflights users on 1/31. 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 3/115:05 am
DEN
- ORD
1 stop6h 45m
Southwest
Wed 3/184:50 pm
ORD
- DEN
Nonstop2h 45m
Southwest
Deal found 1/31![Southwest logo]()
$201
This Delta deal was found by Cheapflights users on 1/31. 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 3/254:00 pm
DEN
- STL
1 stop7h 21m
Delta
Fri 3/276:12 pm
STL
- DEN
1 stop5h 19m
Delta
Deal found 1/31![Delta logo]()
$268
This United Airlines deal was found by Cheapflights users on 2/2. 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 6/197:40 pm
DEN
- ORD
Nonstop2h 39m
United Airlines
Tue 6/236:00 am
ORD
- DEN
Nonstop2h 42m
United Airlines
Deal found 2/2![United Airlines logo]()
$225
This Kiwi.com deal was found by Cheapflights users on 2/2. 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 4/178:00 am
DEN
- STL
1 stop5h 12m
Frontier
Sun 4/1911:21 am
STL
- DEN
2 stops20h 39m
Frontier
Deal found 2/2![Frontier logo]()
$281
Last-minute flights from Denver to IllinoisDiscover last-minute flight deals from Denver to Illinois. Data last updated February 3, 2026 and is based on user searches.
Discover last-minute flight deals from Denver to Illinois. Data last updated February 3, 2026 and is based on user searches.
This Frontier deal was found by Cheapflights users on 1/31. 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.
Wed 2/1812:48 pm
DEN
- STL
Nonstop2h 05m
Frontier
Sat 2/212:51 pm
STL
- DEN
Nonstop2h 27m
Frontier
Deal found 1/31![Frontier logo]()
$111
This Frontier deal was found by Cheapflights users on 2/1. 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 2/2010:01 am
DEN
- STL
Nonstop2h 08m
Frontier
Wed 2/254:51 pm
STL
- DEN
Nonstop2h 34m
Frontier
Deal found 2/1![Frontier logo]()
$80
This Cheapflightsfares deal was found by Cheapflights users on 2/2. 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 2/2010:01 am
DEN
- STL
Nonstop2h 08m
Frontier
Thu 2/2610:11 pm
STL
- DEN
1 stop21h 09m
Frontier
Deal found 2/2![Frontier logo]()
$113
This Expedia deal was found by Cheapflights users on 2/1. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 2/2110:48 am
DEN
- STL
Nonstop2h 08m
Frontier
Mon 2/238:47 pm
STL
- DEN
1 stop12h 07m
Frontier
Deal found 2/1![Frontier logo]()
$107
This Mytrip deal was found by Cheapflights users on 2/1. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/2411:59 pm
DEN
- STL
1 stop21h 28m
Frontier
Fri 2/271:59 pm
STL
- DEN
Nonstop2h 36m
Frontier
Deal found 2/1![Frontier logo]()
$110
This Super.com deal was found by Cheapflights users on 2/1. 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 2/2512:48 pm
DEN
- STL
Nonstop2h 05m
Frontier
Sat 2/282:51 pm
STL
- DEN
Nonstop2h 27m
Frontier
Deal found 2/1![Frontier logo]()
$79
This Kiwi.com deal was found by Cheapflights users on 2/1. 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 2/279:41 am
DEN
- ORD
Nonstop2h 44m
Frontier
Tue 3/311:56 am
ORD
- DEN
1 stop10h 45m
Frontier
Deal found 2/1![Frontier logo]()
$124
This Kiwi.com deal was found by Cheapflights users on 2/1. 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 3/212:59 am
DEN
- STL
1 stop28h 52m
Frontier
Sat 3/78:12 pm
STL
- DEN
Nonstop2h 37m
Frontier
Deal found 2/1![Frontier logo]()
$84
This Kiwi.com deal was found by Cheapflights users on 2/2. 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 3/412:48 pm
DEN
- STL
Nonstop2h 05m
Frontier
Wed 3/1111:32 am
STL
- DEN
1 stop12h 32m
Frontier
Deal found 2/2![Frontier logo]()
$106
This Cheapflightsfares deal was found by Cheapflights users on 2/1. 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 3/219:00 pm
DEN
- ORD
Nonstop2h 38m
Frontier
Tue 4/75:15 am
ORD
- DEN
1 stop7h 54m
Frontier
Deal found 2/1![Frontier logo]()
$120
This Super.com deal was found by Cheapflights users on 1/31. 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 3/276:35 am
DEN
- STL
Nonstop2h 14m
Frontier
Mon 3/308:12 pm
STL
- DEN
Nonstop2h 37m
Frontier
Deal found 1/31![Frontier logo]()
$88
This Expedia deal was found by Cheapflights users on 2/1. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 3/286:35 am
DEN
- STL
Nonstop2h 14m
Frontier
Sat 4/48:16 pm
STL
- DEN
Nonstop2h 33m
Frontier
Deal found 2/1![Frontier logo]()
$93
One-way flights from Denver to IllinoisSearch for one-way flight options from Denver to Illinois. Find affordable one-way fares based on user searches. Data last updated February 3, 2026.
Search for one-way flight options from Denver to Illinois. Find affordable one-way fares based on user searches. Data last updated February 3, 2026.
This Mytrip deal was found by Cheapflights users on 2/3. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 3/136:35 am
DEN
- STL
Nonstop2h 14m
Frontier
Deal found 2/3![Frontier logo]()
$40
This Trip.com deal was found by Cheapflights users on 2/3. 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.
Mon 2/2310:01 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 2/3![Frontier logo]()
$42
This Kiwi.com deal was found by Cheapflights users on 2/1. 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 4/16:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 2/1![Frontier logo]()
$43
This Expedia deal was found by Cheapflights users on 2/3. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/86:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 2/3![Frontier logo]()
$44
This Kiwi.com deal was found by Cheapflights users on 2/3. 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 3/276:35 am
DEN
- STL
Nonstop2h 14m
Frontier
Deal found 2/3![Frontier logo]()
$48
This Kiwi.com deal was found by Cheapflights users on 2/2. 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 2/1310:01 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 2/2![Frontier logo]()
$53
This Kiwi.com deal was found by Cheapflights users on 2/3. 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 3/1011:59 pm
DEN
- STL
1 stop9h 38m
Frontier
Deal found 2/3![Frontier logo]()
$60
This Kiwi.com deal was found by Cheapflights users on 2/1. 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 3/212:59 am
DEN
- STL
1 stop28h 52m
Frontier
Deal found 2/1![Frontier logo]()
$61
This Kiwi.com deal was found by Cheapflights users on 2/2. 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 4/106:40 am
DEN
- STL
Nonstop2h 08m
Frontier
Deal found 2/2![Frontier logo]()
$63
This Cheapflightsfares deal was found by Cheapflights users on 2/3. 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 2/287:24 am
DEN
- STL
1 stop9h 22m
Frontier
Deal found 2/3![Frontier logo]()
$64
This Frontier deal was found by Cheapflights users on 2/3. 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 4/206:15 am
DEN
- ORD
Nonstop2h 35m
Frontier
Deal found 2/3![Frontier logo]()
$84
This Super.com deal was found by Cheapflights users on 2/1. 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 3/189:06 pm
DEN
- ORD
1 stop21h 39m
Frontier
Deal found 2/1![Frontier logo]()
$85
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 February 3, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $79 (Super.com) |
One-way from | $40 (Mytrip) |
Popular in | November |
Cheapest in | August |
Average price | $197 |
Good round-trip deal | $228 or less |
Good one-way deal | $132 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 February 3, 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
DenverSt. Louis
DEN - STL
DENSTL
Denver Intl
Mon 3/23
6:35 am-9:49 am
Nonstop2h 14m
Lambert-St Louis
Fri 3/27
8:12 pm-9:49 pm
Nonstop2h 37m
$114
DenverChicago
DEN - ORD
DENORD
Denver Intl
Tue 3/3
8:30 pm-11:59 pm
Nonstop2h 29m
Chicago O'Hare Intl
Tue 3/10
8:40 am-10:33 am
Nonstop2h 53m
$185
DenverChicago
DEN - MDW
DENMDW
Denver Intl
Thu 4/23
8:20 pm-11:40 pm
Nonstop2h 20m
Chicago Midway
Sat 4/25
3:00 pm-7:00 pm
1 stop5h 00m
$185
DenverChicago
DEN - ORD
DENORD
Denver Intl
Tue 5/12
3:20 pm-6:59 pm
Nonstop2h 39m
Chicago O'Hare Intl
Tue 5/19
2:20 pm-4:16 pm
Nonstop2h 56m
$185
DenverChicago
DEN - MDW
DENMDW
Denver Intl
Fri 4/3
6:20 am-9:45 am
Nonstop2h 25m
Chicago Midway
Mon 4/6
9:40 pm-11:20 pm
Nonstop2h 40m
$191
DenverChicago
DEN - ORD
DENORD
Denver Intl
Sat 2/21
6:00 am-9:38 am
Nonstop2h 38m
Chicago O'Hare Intl
Sun 2/22
8:07 pm-10:05 pm
Nonstop2h 58m
$193
DenverChicago
DEN - MDW
DENMDW
Denver Intl
Thu 3/5
10:25 am-1:50 pm
Nonstop2h 25m
Chicago Midway
Mon 3/9
5:40 pm-7:20 pm
Nonstop2h 40m
$194
DenverChicago
DEN - MDW
DENMDW
Denver Intl
Fri 5/15
6:30 am-2:49 pm
1 stop7h 19m
Chicago Midway
Mon 5/18
6:15 am-11:51 am
1 stop6h 36m
$195
DenverChicago
DEN - MDW
DENMDW
Denver Intl
Thu 4/30
8:20 pm-11:40 pm
Nonstop2h 20m
Chicago Midway
Sat 5/2
6:00 am-7:40 am
Nonstop2h 40m
$195
DenverSt. Louis
DEN - STL
DENSTL
Denver Intl
Thu 3/5
7:24 pm-7:02 am
1 stop10h 38m
Lambert-St Louis
Sat 3/7
7:47 am-10:24 pm
1 stop15h 37m
$197
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.
DEN-STL
DEN-ORD
DEN-MDW
DEN-RFD
DEN-BMI
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
DEN-USIL
DEN-STL
DEN-ORD
DEN-MDW
DEN-RFD
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 February 3, 2026.
It’s optimal to fly from Denver to Illinois in the morning. By choosing this option you can save up to 23% 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 February 3, 2026.
The most flights from DEN to USIL are scheduled on a Tuesday (50 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (29 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 February 3, 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.
Comfort
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Boarding
8.1
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Boarding
8.1
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Boarding
8.1
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Boarding
8.1
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Boarding
8.1
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Comfort
8.0
Food
7.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Boarding
8.1
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.
Complete your trip
Complete your trip to Illinois by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Denver to Illinois by cabin class
Find flights from Denver to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Denver and Illinois flights
Browse other Denver and Illinois flight options. Last updated on February 3, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Denver to Illinois flights
Consider these flights traveling from Denver to Illinois.
Top 6 airlines flying from Denver to Illinois
Discover the top 6 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 February 3, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$61 | Average$176 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$68 | Average$140 | FlexibilityNo cancel fee | On-time88% | |
| Cheapest$126 | Average$191 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$155 | Average$264 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$157 | Average$402 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$157 | Average$341 | FlexibilityNo cancel fee | On-time69% |