$105+ Cheap flights from Colorado to Illinois
This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 1/7. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — ORD
Nov 12 — Nov 191
Round-trip
1 adult, Economy
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Find cheap flights from Colorado to Illinois 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
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Cheapest flights from Colorado to IllinoisExplore the most affordable flight options available from Colorado to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 13, 2026.
Explore the most affordable flight options available from Colorado to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 13, 2026.
This CheapOair deal was found by Cheapflights users on 10/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/203:48 pm -
Nonstop2h 34m
Wed 12/3010:41 pm -
Nonstop2h 55m
Deal found 10/10![Frontier logo]()
$174
This Orbitz deal was found by Cheapflights users on 10/7. 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.
Thu 10/228:55 pm -
Nonstop2h 29m
Mon 10/267:44 pm -
1 stop13h 38m
Deal found 10/7![Frontier logo]()
$175
This Cheapflightsfares deal was found by Cheapflights users on 10/8. 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 11/87:10 pm -
1 stop12h 36m
Sat 11/146:30 am -
Nonstop2h 56m
Deal found 10/8![Frontier logo]()
$176
This Super.com deal was found by Cheapflights users on 10/9. 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 12/173:48 pm -
Nonstop2h 34m
Wed 12/2310:41 pm -
Nonstop2h 55m
Deal found 10/9![Frontier logo]()
$177
This Cheapflightsfares deal was found by Cheapflights users on 10/9. 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 11/198:55 pm -
Nonstop2h 26m
Sun 11/226:40 am -
Nonstop2h 56m
Deal found 10/9![Frontier logo]()
$178
This Cheapflightsfares deal was found by Cheapflights users on 10/9. 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 10/278:55 pm -
Nonstop2h 26m
Thu 10/2910:40 am -
1 stop6h 13m
Deal found 10/9![Frontier logo]()
$179
This Cheapflightsfares deal was found by Cheapflights users on 10/9. 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 11/68:55 pm -
Nonstop2h 26m
Mon 11/99:51 am -
1 stop23h 22m
Deal found 10/9![Frontier logo]()
$180
This Cheapflightsfares deal was found by Cheapflights users on 10/8. 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 12/511:59 pm -
1 stop19h 43m
Tue 12/812:28 pm -
1 stop8h 27m
Deal found 10/8![Frontier logo]()
$180
This Mytrip deal was found by Cheapflights users on 10/9. 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 11/68:55 pm -
Nonstop2h 26m
Fri 11/137:25 pm -
1 stop13h 54m
Deal found 10/9![Multiple Airlines logo]()
$181
This Mytrip deal was found by Cheapflights users on 10/8. 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.
Thu 11/57:30 am -
1 stop20h 43m
Mon 11/97:50 pm -
2 stops21h 03m
Deal found 10/8![Frontier logo]()
$182
This Frontier deal was found by Cheapflights users on 10/11. 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 11/249:26 pm -
Nonstop2h 27m
Fri 12/47:00 am -
Nonstop3h 02m
Deal found 10/11![Frontier logo]()
$183
This Trip.com deal was found by Cheapflights users on 10/7. 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 11/410:43 am -
1 stop6h 04m
Sat 11/712:20 pm -
1 stop10h 14m
Deal found 10/7![Frontier logo]()
$183
Best flights from Colorado to IllinoisDiscover carefully curated flight deals from Colorado to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 13, 2026.
Discover carefully curated flight deals from Colorado to Illinois that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated October 13, 2026.
This Southwest deal was found by Cheapflights users on 10/8. 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 11/172:05 pm -
Nonstop2h 20m
Wed 11/188:05 am -
Nonstop2h 55m
Deal found 10/8![Southwest logo]()
$189
This United Airlines deal was found by Cheapflights users on 10/12. 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 11/67:12 pm -
Nonstop2h 34m
Mon 11/95:48 pm -
Nonstop2h 57m
Deal found 10/12![United Airlines logo]()
$243
This Delta deal was found by Cheapflights users on 10/8. 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 11/1911:08 am -
1 stop4h 33m
Mon 11/236:23 am -
1 stop4h 35m
Deal found 10/8![Delta logo]()
$253
This American Airlines deal was found by Cheapflights users on 10/7. 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 10/303:14 pm -
2 stops7h 57m
Sun 11/15:03 pm -
1 stop6h 51m
Deal found 10/7![American Airlines logo]()
$344
This Southwest deal was found by Cheapflights users on 10/8. 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 12/37:05 am -
Nonstop2h 25m
Mon 12/78:55 pm -
Nonstop2h 40m
Deal found 10/8![Southwest logo]()
$189
This Sun Country Air deal was found by Cheapflights users on 10/8. 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.
Thu 12/247:15 pm -
1 stop14h 08m
Sun 12/278:10 pm -
1 stop14h 23m
Deal found 10/8![Sun Country Air logo]()
$405
This Southwest deal was found by Cheapflights users on 10/8. 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 10/294:20 pm -
1 stop3h 35m
Mon 11/25:20 am -
1 stop5h 35m
Deal found 10/8![Southwest logo]()
$204
This Delta deal was found by Cheapflights users on 10/12. 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 12/106:10 am -
1 stop6h 46m
Wed 1/66:00 am -
1 stop5h 12m
Deal found 10/12![Delta logo]()
$263
This United Airlines deal was found by Cheapflights users on 10/9. 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 11/127:12 pm -
Nonstop2h 34m
Sun 11/159:00 pm -
Nonstop2h 44m
Deal found 10/9![United Airlines logo]()
$270
This Delta deal was found by Cheapflights users on 10/12. 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.
Tue 12/811:13 am -
1 stop4h 30m
Tue 1/56:00 am -
1 stop5h 12m
Deal found 10/12![Delta logo]()
$263
This Southwest deal was found by Cheapflights users on 10/9. 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 12/117:10 am -
Nonstop2h 20m
Mon 12/148:05 am -
Nonstop2h 55m
Deal found 10/9![Southwest logo]()
$243
This Delta deal was found by Cheapflights users on 10/8. 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.
Sun 10/2512:59 am -
1 stop7h 33m
Mon 11/21:27 pm -
1 stop5h 05m
Deal found 10/8![Delta logo]()
$264
This Southwest deal was found by Cheapflights users on 10/10. 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 11/96:45 pm -
Nonstop2h 15m
Mon 11/161:20 pm -
1 stop5h 05m
Deal found 10/10![Southwest logo]()
$249
This American Airlines deal was found by Cheapflights users on 10/10. 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 12/46:00 am -
1 stop9h 09m
Sun 12/66:25 pm -
1 stop7h 06m
Deal found 10/10![American Airlines logo]()
$349
This Delta deal was found by Cheapflights users on 10/8. 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 11/71:26 pm -
1 stop8h 07m
Tue 11/106:00 am -
1 stop7h 26m
Deal found 10/8![Delta logo]()
$267
This Southwest deal was found by Cheapflights users on 10/12. 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 11/61:20 pm -
1 stop3h 25m
Mon 11/95:40 pm -
Nonstop2h 45m
Deal found 10/12![Southwest logo]()
$249
This United Airlines deal was found by Cheapflights users on 10/8. 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 2/211:26 am -
1 stop6h 24m
Wed 2/37:45 pm -
Nonstop3h 14m
Deal found 10/8![United Airlines logo]()
$357
This Delta deal was found by Cheapflights users on 10/8. 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 11/1210:36 am -
1 stop6h 54m
Sun 11/156:23 am -
1 stop4h 35m
Deal found 10/8![Delta logo]()
$272
This Southwest deal was found by Cheapflights users on 10/10. 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 11/125:20 pm -
1 stop5h 50m
Mon 11/166:05 am -
Nonstop2h 55m
Deal found 10/10![Southwest logo]()
$253
This United Airlines deal was found by Cheapflights users on 10/11. 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 1/73:35 pm -
1 stop7h 23m
Mon 1/117:00 am -
1 stop6h 26m
Deal found 10/11![United Airlines logo]()
$359
This Delta deal was found by Cheapflights users on 10/8. 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 11/71:26 pm -
1 stop8h 07m
Sat 11/1410:34 am -
2 stops11h 16m
Deal found 10/8![Delta logo]()
$272
This American Airlines deal was found by Cheapflights users on 10/12. 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 10/285:00 pm -
1 stop5h 59m
Sun 11/15:29 pm -
1 stop8h 01m
Deal found 10/12![American Airlines logo]()
$399
This Southwest deal was found by Cheapflights users on 10/8. 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 11/42:25 pm -
1 stop4h 15m
Sun 11/85:55 am -
Nonstop2h 50m
Deal found 10/8![Southwest logo]()
$258
This United Airlines deal was found by Cheapflights users on 10/11. 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 11/91:40 pm -
1 stop6h 50m
Wed 11/117:00 am -
1 stop6h 36m
Deal found 10/11![United Airlines logo]()
$359
This Delta deal was found by Cheapflights users on 10/8. 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.
Tue 11/31:31 pm -
1 stop6h 07m
Sat 11/79:59 am -
2 stops8h 28m
Deal found 10/8![Delta logo]()
$272
This American Airlines deal was found by Cheapflights users on 10/8. 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.
Thu 1/281:07 pm -
Nonstop3h 15m
Sun 1/319:40 am -
Nonstop3h 57m
Deal found 10/8![American Airlines logo]()
$413
This Southwest deal was found by Cheapflights users on 10/8. 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 11/125:20 pm -
1 stop5h 50m
Sun 11/158:55 am -
Nonstop2h 50m
Deal found 10/8![Southwest logo]()
$262
This United Airlines deal was found by Cheapflights users on 10/9. 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 11/51:40 pm -
1 stop5h 49m
Mon 11/97:00 am -
1 stop6h 36m
Deal found 10/9![United Airlines logo]()
$359
This American Airlines deal was found by Cheapflights users on 10/9. 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.
Thu 12/37:30 am -
1 stop7h 30m
Sun 12/66:00 am -
1 stop7h 30m
Deal found 10/9![American Airlines logo]()
$433
This United Airlines deal was found by Cheapflights users on 10/9. 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 11/101:40 pm -
1 stop6h 50m
Wed 11/113:56 pm -
1 stop5h 34m
Deal found 10/9![United Airlines logo]()
$359
Last-minute flights from Colorado to IllinoisDiscover last-minute flight deals from Colorado to Illinois. Data last updated October 13, 2026 and is based on user searches.
Discover last-minute flight deals from Colorado to Illinois. Data last updated October 13, 2026 and is based on user searches.
This Cheapflightsfares deal was found by Cheapflights users on 10/8. 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 10/218:55 pm -
Nonstop2h 29m
Wed 10/286:30 am -
Nonstop2h 56m
Deal found 10/8![Frontier logo]()
$177
This Kiwi.com deal was found by Cheapflights users on 10/8. 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 10/218:55 pm -
Nonstop2h 29m
Tue 10/276:30 am -
Nonstop2h 56m
Deal found 10/8![Frontier logo]()
$199
This Orbitz deal was found by Cheapflights users on 10/7. 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.
Thu 10/228:55 pm -
Nonstop2h 29m
Mon 10/267:44 pm -
1 stop13h 38m
Deal found 10/7![Frontier logo]()
$175
This Cheapflightsfares deal was found by Cheapflights users on 10/8. 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 10/2510:20 am -
Nonstop1h 59m
Sun 11/15:24 pm -
Nonstop2h 20m
Deal found 10/8![Allegiant Air logo]()
$200
This Kiwi.com deal was found by Cheapflights users on 10/8. 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 10/269:12 pm -
2 stops34h 49m
Sun 11/15:24 pm -
Nonstop2h 20m
Deal found 10/8![Multiple Airlines logo]()
$193
This Southwest deal was found by Cheapflights users on 10/8. 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 10/2811:00 am -
1 stop4h 05m
Sat 10/319:35 am -
Nonstop2h 40m
Deal found 10/8![Southwest logo]()
$195
This Cheapflightsfares deal was found by Cheapflights users on 10/7. 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 10/2810:43 am -
1 stop12h 04m
Fri 10/3012:20 pm -
1 stop10h 22m
Deal found 10/7![Frontier logo]()
$200
This Frontier deal was found by Cheapflights users on 10/8. 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 10/2910:41 am -
1 stop6h 06m
Wed 11/412:27 pm -
1 stop10h 15m
Deal found 10/8![Frontier logo]()
$186
This Kiwi.com deal was found by Cheapflights users on 10/8. 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 11/39:20 pm -
1 stop13h 02m
Mon 11/96:42 pm -
1 stop14h 40m
Deal found 10/8![Frontier logo]()
$187
This Trip.com deal was found by Cheapflights users on 10/7. 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 11/410:43 am -
1 stop6h 04m
Sat 11/712:20 pm -
1 stop10h 14m
Deal found 10/7![Frontier logo]()
$183
This Southwest deal was found by Cheapflights users on 10/8. 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 11/76:35 am -
Nonstop2h 20m
Sat 11/146:25 pm -
Nonstop2h 55m
Deal found 10/8![Southwest logo]()
$189
This Southwest deal was found by Cheapflights users on 10/7. 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 11/1110:55 am -
1 stop5h 00m
Thu 11/129:25 pm -
Nonstop2h 50m
Deal found 10/7![Southwest logo]()
$199
One-way flights from Colorado to IllinoisSearch for one-way flight options from Colorado to Illinois. Find affordable one-way fares based on user searches. Data last updated October 13, 2026.
Search for one-way flight options from Colorado to Illinois. Find affordable one-way fares based on user searches. Data last updated October 13, 2026.
This Super.com deal was found by Cheapflights users on 10/8. 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 11/67:10 pm -
1 stop27h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/8![Frontier logo]()
$105
This Mytrip deal was found by Cheapflights users on 10/8. 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.
Mon 10/269:12 pm -
2 stops19h 15m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/8![Frontier logo]()
$105
This Super.com deal was found by Cheapflights users on 10/9. 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 10/2910:47 am -
1 stop7h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/9![Frontier logo]()
$106
This Kiwi.com deal was found by Cheapflights users on 10/8. 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 11/99:19 pm -
1 stop13h 03m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/8![Frontier logo]()
$106
This Kiwi.com deal was found by Cheapflights users on 10/11. 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 12/203:48 pm -
Nonstop2h 34m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/11![Frontier logo]()
$107
This Priceline deal was found by Cheapflights users on 10/10. 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.
Tue 11/34:17 pm -
1 stop5h 56m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/10![Frontier logo]()
$109
This Cheapflightsfares deal was found by Cheapflights users on 10/10. 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 11/1710:41 am -
1 stop6h 06m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/10![Frontier logo]()
$109
This Southwest deal was found by Cheapflights users on 10/7. 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 11/265:50 am -
2 stops8h 00m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/7![Southwest logo]()
$110
This Super.com deal was found by Cheapflights users on 10/7. 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 11/209:26 pm -
Nonstop2h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/7![Frontier logo]()
$111
This Kiwi.com deal was found by Cheapflights users on 10/10. 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 12/128:07 pm -
1 stop17h 48m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/10![Frontier logo]()
$111
This Cheapflightsfares deal was found by Cheapflights users on 10/10. 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.
Mon 12/215:52 pm -
Nonstop2h 29m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/10![Frontier logo]()
$112
This Expedia deal was found by Cheapflights users on 10/9. 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.
Fri 3/58:59 pm -
Nonstop2h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 10/9![Frontier logo]()
$113
Find flight deals from Colorado to Illinois
Keep the following information in mind while searching for Colorado to Illinois flight deals. Data was last updated October 13, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $174 (CheapOair) |
One-way from | $105 (Super.com) |
Popular in | July |
Cheapest in | January |
Average price | $284 |
Good round-trip deal | $248 or less |
Good one-way deal | $181 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Colorado 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 7,457,451 searches. Data last updated October 13, 2026.
Use the filters below to find and compare flights from Colorado to Illinois that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
DenverChicago
DEN Denver Intl - ORD Chicago O'Hare Intl
DENORD
Denver Intl
Thu 1/7
6:45 am-12:37 pm
1 stop4h 52m
Chicago O'Hare Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$105
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Sat 11/7
6:00 am-2:30 pm
2 stops7h 30m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$110
DenverChicago
DEN Denver Intl - ORD Chicago O'Hare Intl
DENORD
Denver Intl
Fri 1/1
8:57 pm-12:30 am
Nonstop2h 33m
Chicago O'Hare Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$122
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Sat 12/12
5:30 pm-8:50 pm
Nonstop2h 20m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$122
Quickest round-trip
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Tue 12/29
6:45 pm-10:00 pm
Nonstop2h 15m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$122
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Thu 12/31
6:05 pm-9:25 pm
Nonstop2h 20m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$122
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Fri 11/27
8:40 pm-11:55 pm
Nonstop2h 15m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$122
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Sat 12/5
5:30 pm-8:50 pm
Nonstop2h 20m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$122
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Wed 12/9
8:55 am-12:15 pm
Nonstop2h 20m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$122
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Fri 12/4
7:05 am-10:30 am
Nonstop2h 25m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$129
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Colorado to Illinois
Have a flexible travel schedule? Discover the best time to fly to Illinois from Colorado with our price prediction graph.
DEN-ORD
DEN-MDW
DEN-MLI
COS-MDW
COS-ORD
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 Colorado to Illinois
USCO-USIL
DEN-ORD
DEN-MDW
DEN-MLI
COS-MDW
What is the cheapest month to book a flight from Colorado to Illinois?
Currently, January is the cheapest month in which you can book a flight from Colorado to Illinois (average of $249). Flying from Colorado to Illinois in July is currently the most expensive (average of $356). 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 CO to IL?
Find hourly flight availability from Colorado 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 October 13, 2026.
A simple way to save on the total cost of your ticket is to fly from Colorado to Illinois in the evening. If you’re flexible enough to do this you can expect to save up to 24% on your trip compared to booking a flight in the morning.
Weekly flight availability from Colorado to Illinois
Explore weekly flight availability from Colorado 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 October 13, 2026.
The most flights from USCO to USIL are scheduled on a Monday (77 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (52 on average).
How much does it cost to fly round-trip from Colorado to Illinois?
Airfare is below average for this route at the moment.
Colorado to Illinois flights typically cost between $238 and $392 in December.The cheapest round-trip price found within the last 5 days was $174 on Frontier (Dec 20-Dec 30).
How far ahead should I book a flight from Colorado to Illinois?
To ensure you get the cheapest price possible for a flight from Colorado to Illinois, you should look to book at least 89 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 Colorado to Illinois?
Use this chart to determine the cheapest time to fly round-trip from Colorado to Illinois. Price data was last updated on October 10, 2026.
Travelers seeking maximum savings on their Colorado to Illinois flight should consider departing on Friday at noon 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.
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 October 13, 2026.
Read reviews from past customers who have flown Southwest,United Airlines, andAllegiant Air from Colorado to Illinois. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Entertainment
7.5
Comfort
8.0
Boarding
8.1
Food
7.0
Overall
7.9
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Entertainment
7.5
Comfort
8.0
Boarding
8.1
Food
7.0
Overall
7.9
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Entertainment
7.5
Comfort
8.0
Boarding
8.1
Food
7.0
Overall
7.9
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Entertainment
7.5
Comfort
8.0
Boarding
8.1
Food
7.0
Overall
7.9
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Entertainment
7.5
Comfort
8.0
Boarding
8.1
Food
7.0
Overall
7.9
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Entertainment
7.5
Comfort
8.0
Boarding
8.1
Food
7.0
Overall
7.9
Crew
8.6
Reviews
1 / 20
6.0
GoodReza,Jun 2026
TPA - MDW
Related info for your journey
Find useful and relevant information for your journey from Colorado to Illinois. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.
Browse thousands of different options on Cheapflights for your next trip
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Alternative routes for Colorado 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 Colorado to Illinois by cabin class
Find flights from Colorado to Illinois, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Colorado and Illinois flights
Browse other Colorado and Illinois flight options. Last updated on October 13, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Find a return flight route from Illinois
Find the right flight back to Colorado after your stay in Illinois
Colorado to Illinois flights
Consider these flights traveling from Colorado to Illinois.
Top 6 airlines flying from Colorado to Illinois
Discover the top 6 airlines that operate flights from Colorado 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 7,457,451 searches. Data last updated October 13, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$82 | Average$201 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$100 | Average$232 | FlexibilityNo cancel fee | On-time88% | |
| Cheapest$138 | Average$281 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$170 | Average$348 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$176 | Average$400 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$189 | Average$472 | FlexibilityNo cancel fee | On-time69% |