$96+ 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 12/2. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — ORD
Dec 9 — Dec 161
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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Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.Cheap flight deals from Colorado to Illinois
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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 November 9, 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 November 9, 2026.
This Kiwi.com deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” 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 12/98:00 am -
2 stops13h 00m
Sat 12/127:25 am -
Nonstop3h 04m
Deal found 11/6![Frontier logo]()
$186
This Mytrip deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/310:55 pm -
2 stops19h 49m
Sat 12/127:25 am -
Nonstop3h 04m
Deal found 11/5![Frontier logo]()
$188
This Cheapflightsfares deal was found by Cheapflights users on 11/9. 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 12/228:59 pm -
Nonstop2h 27m
Mon 1/47:05 am -
Nonstop3h 04m
Deal found 11/9![Frontier logo]()
$189
This Kiwi.com deal was found by Cheapflights users on 11/8. 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 12/29:26 pm -
Nonstop2h 27m
Mon 12/77:25 am -
Nonstop3h 04m
Deal found 11/8![Frontier logo]()
$190
This FlightHub deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/19:00 am -
1 stop11h 35m
Fri 12/47:00 am -
Nonstop3h 02m
Deal found 11/6![Frontier logo]()
$191
This Cheapflightsfares deal was found by Cheapflights users on 11/8. 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.
Mon 11/3011:59 pm -
1 stop10h 45m
Wed 12/27:00 am -
Nonstop3h 02m
Deal found 11/8![Frontier logo]()
$192
This Cheapflightsfares deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/48:46 pm -
1 stop11h 59m
Tue 12/812:28 pm -
1 stop8h 29m
Deal found 11/5![Frontier logo]()
$192
This Cheapflightsfares deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/49:26 pm -
Nonstop2h 27m
Sun 12/65:35 am -
1 stop16h 55m
Deal found 11/5![Frontier logo]()
$193
This Cheapflightsfares deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/410:25 am -
1 stop8h 19m
Tue 12/810:00 am -
1 stop12h 55m
Deal found 11/5![Frontier logo]()
$194
This Cheapflightsfares deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/76:41 am -
1 stop9h 35m
Sat 12/1210:40 am -
1 stop12h 15m
Deal found 11/5![Frontier logo]()
$194
This Kiwi.com deal was found by Cheapflights users on 11/8. 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 12/710:26 am -
1 stop8h 22m
Wed 12/97:25 am -
Nonstop3h 04m
Deal found 11/8![Frontier logo]()
$195
This Cheapflightsfares deal was found by Cheapflights users on 11/9. 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 12/111:59 pm -
1 stop24h 00m
Sun 12/67:00 am -
Nonstop3h 04m
Deal found 11/9![Frontier logo]()
$196
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 November 9, 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 November 9, 2026.
This Delta deal was found by Cheapflights users on 11/4. Clicking the “Pick Dates” 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 12/211:13 am -
1 stop4h 30m
Wed 12/911:39 am -
1 stop6h 35m
Deal found 11/4![Delta logo]()
$241
This United Airlines deal was found by Cheapflights users on 11/4. Clicking the “Pick Dates” 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 12/2411:15 am -
Nonstop2h 40m
Thu 12/248:23 pm -
Nonstop2h 59m
Deal found 11/4![United Airlines logo]()
$243
This Southwest deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/310:55 am -
1 stop5h 00m
Thu 12/105:00 pm -
1 stop6h 05m
Deal found 11/5![Southwest logo]()
$263
This American Airlines deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 1/215:18 pm -
1 stop5h 41m
Sun 1/243:05 pm -
1 stop7h 28m
Deal found 11/5![American Airlines logo]()
$368
This Alaska Airlines deal was found by Cheapflights users on 11/8. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/87:40 am -
2 stops15h 19m
Sat 12/126:00 am -
1 stop13h 26m
Deal found 11/8![Alaska Airlines logo]()
$508
This Southwest deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” 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 1/611:25 am -
1 stop3h 55m
Sat 1/96:30 am -
Nonstop2h 45m
Deal found 11/6![Southwest logo]()
$271
This Delta deal was found by Cheapflights users on 11/8. 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.
Wed 12/211:13 am -
1 stop4h 37m
Thu 12/1010:24 am -
1 stop6h 38m
Deal found 11/8![Delta logo]()
$297
This United Airlines deal was found by Cheapflights users on 11/4. Clicking the “Pick Dates” 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 12/243:25 pm -
Nonstop2h 40m
Wed 12/3010:00 pm -
Nonstop2h 53m
Deal found 11/4![United Airlines logo]()
$314
This Southwest deal was found by Cheapflights users on 11/9. 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 12/188:55 pm -
Nonstop2h 20m
Tue 12/2210:50 pm -
Nonstop2h 50m
Deal found 11/9![Southwest logo]()
$290
This United Airlines deal was found by Cheapflights users on 11/4. Clicking the “Pick Dates” 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 11/2512:02 pm -
Nonstop2h 51m
Thu 11/267:00 am -
1 stop4h 33m
Deal found 11/4![United Airlines logo]()
$317
This Southwest deal was found by Cheapflights users on 11/9. 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 2/128:45 pm -
Nonstop2h 25m
Tue 2/167:50 pm -
Nonstop2h 45m
Deal found 11/9![Southwest logo]()
$290
This Delta deal was found by Cheapflights users on 11/9. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/2812:55 am -
1 stop6h 54m
Sat 1/26:30 pm -
1 stop5h 45m
Deal found 11/9![Delta logo]()
$325
This American Airlines deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/101:23 pm -
1 stop8h 41m
Thu 1/75:00 am -
1 stop8h 53m
Deal found 11/5![American Airlines logo]()
$379
This United Airlines deal was found by Cheapflights users on 11/4. Clicking the “Pick Dates” 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 1/218:45 am -
1 stop5h 10m
Sat 1/235:45 pm -
1 stop5h 24m
Deal found 11/4![United Airlines logo]()
$327
This Southwest deal was found by Cheapflights users on 11/7. 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 12/911:05 am -
1 stop5h 00m
Sat 12/1211:05 am -
2 stops7h 35m
Deal found 11/7![Southwest logo]()
$301
This Delta deal was found by Cheapflights users on 11/4. Clicking the “Pick Dates” 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 1/218:06 am -
2 stops11h 26m
Sat 1/237:10 am -
1 stop6h 24m
Deal found 11/4![Delta logo]()
$332
This United Airlines deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” 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 12/187:40 am -
Nonstop2h 39m
Sun 12/206:50 am -
Nonstop2h 53m
Deal found 11/6![United Airlines logo]()
$330
This Delta deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/58:02 am -
2 stops11h 51m
Mon 12/75:30 am -
1 stop8h 03m
Deal found 11/5![Delta logo]()
$332
This KAYAK deal was found by Cheapflights users on 11/9. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 1/1011:37 am -
1 stop8h 17m
Tue 1/1210:35 pm -
Nonstop2h 53m
Deal found 11/9![American Airlines logo]()
$415
This Southwest deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/316:05 pm -
Nonstop2h 25m
Sun 1/36:00 am -
Nonstop2h 45m
Deal found 11/5![Southwest logo]()
$324
This Delta deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” 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 1/112:55 am -
1 stop7h 54m
Mon 1/46:00 am -
1 stop7h 22m
Deal found 11/6![Delta logo]()
$340
This United Airlines deal was found by Cheapflights users on 11/4. Clicking the “Pick Dates” 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 12/46:00 am -
Nonstop2h 40m
Fri 12/48:07 pm -
Nonstop2h 52m
Deal found 11/4![United Airlines logo]()
$343
This Alaska Airlines deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/67:00 am -
1 stop15h 59m
Wed 12/96:00 am -
2 stops14h 26m
Deal found 11/6![Alaska Airlines logo]()
$518
This Southwest deal was found by Cheapflights users on 11/9. 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.
Thu 1/1411:25 am -
1 stop3h 55m
Sun 1/176:15 am -
Nonstop2h 45m
Deal found 11/9![Southwest logo]()
$326
This American Airlines deal was found by Cheapflights users on 11/9. 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 1/281:57 pm -
1 stop8h 23m
Sun 1/319:40 am -
Nonstop3h 57m
Deal found 11/9![American Airlines logo]()
$453
This United Airlines deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” 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 12/811:43 am -
Nonstop2h 47m
Thu 12/107:52 pm -
Nonstop3h 07m
Deal found 11/6![United Airlines logo]()
$344
This Delta deal was found by Cheapflights users on 11/9. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/121:40 pm -
1 stop8h 14m
Tue 12/1512:39 pm -
2 stops10h 45m
Deal found 11/9![Delta logo]()
$354
This Southwest deal was found by Cheapflights users on 11/9. 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.
Tue 12/12:05 pm -
Nonstop2h 20m
Sun 12/69:25 pm -
Nonstop2h 50m
Deal found 11/9![Southwest logo]()
$335
This Delta deal was found by Cheapflights users on 11/9. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 12/510:35 am -
1 stop4h 42m
Sun 12/66:20 am -
1 stop4h 47m
Deal found 11/9![Delta logo]()
$355
This United Airlines deal was found by Cheapflights users on 11/8. 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.
Wed 12/304:40 pm -
1 stop5h 02m
Fri 1/87:00 am -
1 stop6h 31m
Deal found 11/8![United Airlines logo]()
$364
Last-minute flights from Colorado to IllinoisDiscover last-minute flight deals from Colorado to Illinois. Data last updated November 9, 2026 and is based on user searches.
Discover last-minute flight deals from Colorado to Illinois. Data last updated November 9, 2026 and is based on user searches.
This Cheapflightsfares deal was found by Cheapflights users on 11/8. 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.
Mon 11/3011:59 pm -
1 stop10h 45m
Wed 12/27:00 am -
Nonstop3h 02m
Deal found 11/8![Frontier logo]()
$192
This FlightHub deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/19:00 am -
1 stop11h 35m
Fri 12/47:00 am -
Nonstop3h 02m
Deal found 11/6![Frontier logo]()
$191
This Cheapflightsfares deal was found by Cheapflights users on 11/9. 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 12/111:59 pm -
1 stop24h 00m
Sun 12/67:00 am -
Nonstop3h 04m
Deal found 11/9![Frontier logo]()
$196
This Kiwi.com deal was found by Cheapflights users on 11/8. 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 12/29:26 pm -
Nonstop2h 27m
Mon 12/77:25 am -
Nonstop3h 04m
Deal found 11/8![Frontier logo]()
$190
This Mytrip deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/310:55 pm -
2 stops19h 49m
Sat 12/127:25 am -
Nonstop3h 04m
Deal found 11/5![Frontier logo]()
$188
This Cheapflightsfares deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/48:46 pm -
1 stop11h 59m
Tue 12/812:28 pm -
1 stop8h 29m
Deal found 11/5![Frontier logo]()
$192
This Cheapflightsfares deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/49:26 pm -
Nonstop2h 27m
Sun 12/65:35 am -
1 stop16h 55m
Deal found 11/5![Frontier logo]()
$193
This Cheapflightsfares deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/410:25 am -
1 stop8h 19m
Tue 12/810:00 am -
1 stop12h 55m
Deal found 11/5![Frontier logo]()
$194
This Cheapflightsfares deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/76:41 am -
1 stop9h 35m
Sat 12/1210:40 am -
1 stop12h 15m
Deal found 11/5![Frontier logo]()
$194
This Kiwi.com deal was found by Cheapflights users on 11/8. 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 12/710:26 am -
1 stop8h 22m
Wed 12/97:25 am -
Nonstop3h 04m
Deal found 11/8![Frontier logo]()
$195
This Kiwi.com deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” 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 12/98:00 am -
2 stops13h 00m
Sat 12/127:25 am -
Nonstop3h 04m
Deal found 11/6![Frontier logo]()
$186
This Kiwi.com deal was found by Cheapflights users on 11/9. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/228:59 pm -
Nonstop2h 27m
Tue 1/56:10 am -
Nonstop3h 00m
Deal found 11/9![Frontier logo]()
$189
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 November 9, 2026.
Search for one-way flight options from Colorado to Illinois. Find affordable one-way fares based on user searches. Data last updated November 9, 2026.
This Super.com deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” 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 12/29:26 pm -
Nonstop2h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/6![Frontier logo]()
$96
This Kiwi.com deal was found by Cheapflights users on 11/6. Clicking the “Pick Dates” 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 2/2010:29 pm -
1 stop7h 36m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/6![Frontier logo]()
$97
This Super.com deal was found by Cheapflights users on 11/9. 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.
Fri 12/119:26 pm -
Nonstop2h 28m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/9![Frontier logo]()
$98
This Kiwi.com deal was found by Cheapflights users on 11/7. 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 Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/79:26 pm -
Nonstop2h 28m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/7![Frontier logo]()
$99
This Expedia deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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.
Tue 12/158:40 pm -
1 stop12h 05m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/5![Frontier logo]()
$99
This Cheapflightsfares deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 12/56:59 pm -
1 stop9h 02m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/5![Frontier logo]()
$100
This Cheapflightsfares deal was found by Cheapflights users on 11/9. 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 12/39:26 pm -
Nonstop2h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/9![Frontier logo]()
$101
This Frontier deal was found by Cheapflights users on 11/5. Clicking the “Pick Dates” 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 3/310:41 am -
1 stop8h 01m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/5![Frontier logo]()
$101
This iWofly deal was found by Cheapflights users on 11/9. 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 iWofly is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 1/78:59 pm -
Nonstop2h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/9![Frontier logo]()
$102
This Cheapflightsfares deal was found by Cheapflights users on 11/9. 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 12/227:08 pm -
1 stop9h 41m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/9![Frontier logo]()
$103
This CheapOair deal was found by Cheapflights users on 11/9. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/118:40 pm -
1 stop12h 05m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/9![Frontier logo]()
$104
This United Airlines deal was found by Cheapflights users on 11/8. 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 12/89:35 am -
Nonstop2h 40m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 11/8![United Airlines logo]()
$105
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 November 9, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $186 (Frontier) |
One-way from | $96 (Super.com) |
Popular in | July |
Cheapest in | January |
Average price | $302 |
Good round-trip deal | $201 or less |
Good one-way deal | $172 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 November 9, 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
Tue 12/8
9:35 am-1:15 pm
Nonstop2h 40m
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
Tue 12/15
6:05 pm-9:30 pm
Nonstop2h 25m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$105
DenverChicago
DEN Denver Intl - ORD Chicago O'Hare Intl
DENORD
Denver Intl
Fri 11/27
5:58 pm-9:30 pm
Nonstop2h 32m
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
Wed 1/6
11:10 am-4:45 pm
1 stop4h 35m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$127
DenverChicago
DEN Denver Intl - ORD Chicago O'Hare Intl
DENORD
Denver Intl
Fri 1/1
5:50 am-9:34 am
Nonstop2h 44m
Chicago O'Hare Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$128
DenverChicago
DEN Denver Intl - ORD Chicago O'Hare Intl
DENORD
Denver Intl
Tue 12/1
6:10 am-1:56 pm
1 stop6h 46m
Chicago O'Hare Intl
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$132
Quickest round-trip
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Tue 12/22
8:55 pm-12:15 am
Nonstop2h 20m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$133
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Tue 2/23
6:50 am-10:15 am
Nonstop2h 25m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$133
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Sat 12/19
9:30 pm-12:50 am
Nonstop2h 20m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$133
DenverChicago
DEN Denver Intl - MDW Chicago Midway
DENMDW
Denver Intl
Tue 12/1
6:05 pm-9:30 pm
Nonstop2h 25m
Chicago Midway
Wed 12/31
12:00 am-11:00 pm
Nonstop0h 00m
$133
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-PIA
COS-ORD
DEN-MLI
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-PIA
COS-ORD
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 $248). Flying from Colorado to Illinois in October is currently the most expensive (average of $358). 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 November 9, 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 20% 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 November 9, 2026.
The most flights from USCO to USIL are scheduled on a Friday (74 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (59 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 $259 and $463 in November.The cheapest round-trip price found within the last 5 days was $186 on Frontier (Nov 25-Dec 2).
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 November 7, 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. Tuesday at noon 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 November 9, 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.
Crew
8.6
Entertainment
7.4
Comfort
8.0
Overall
8.0
Food
7.0
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
Crew
8.6
Entertainment
7.4
Comfort
8.0
Overall
8.0
Food
7.0
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
Crew
8.6
Entertainment
7.4
Comfort
8.0
Overall
8.0
Food
7.0
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
Crew
8.6
Entertainment
7.4
Comfort
8.0
Overall
8.0
Food
7.0
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
Crew
8.6
Entertainment
7.4
Comfort
8.0
Overall
8.0
Food
7.0
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
Crew
8.6
Entertainment
7.4
Comfort
8.0
Overall
8.0
Food
7.0
Boarding
8.1
Reviews
1 / 20
10.0
ExcellentCourtney,Sep 2026
DEN - STL
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.
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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 November 9, 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 November 9, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$82 | Average$216 | 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$362 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$176 | Average$408 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$194 | Average$475 | FlexibilityNo cancel fee | On-time69% |