$68+ Cheap flights from Illinois to Colorado
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 11/1. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — DEN
Oct 13 — Oct 201
Round-trip
1 adult, Economy
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Find cheap flights from Illinois to Colorado 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 Illinois to ColoradoExplore the most affordable flight options available from Illinois to Colorado. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 13, 2026.
Explore the most affordable flight options available from Illinois to Colorado. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 13, 2026.
This Frontier deal was found by Cheapflights users on 9/10. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 12/147:49 pm -
Nonstop2h 31m
Thu 12/176:10 am -
1 stop7h 47m
Deal found 9/10![Frontier logo]()
$126
This Kiwi.com deal was found by Cheapflights users on 9/9. 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.
Sat 10/177:42 pm -
Nonstop2h 27m
Tue 10/206:57 pm -
1 stop21h 43m
Deal found 9/9![Frontier logo]()
$127
This Cheapflightsfares deal was found by Cheapflights users on 9/10. 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.
Fri 10/231:30 pm -
1 stop7h 20m
Mon 10/264:12 pm -
Nonstop2h 03m
Deal found 9/10![Frontier logo]()
$128
This FlightHub deal was found by Cheapflights users on 9/8. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/191:30 pm -
1 stop24h 18m
Sat 10/243:54 pm -
Nonstop2h 03m
Deal found 9/8![Frontier logo]()
$132
This Frontier deal was found by Cheapflights users on 9/9. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/284:18 pm -
Nonstop2h 30m
Sat 10/3110:40 am -
1 stop11h 36m
Deal found 9/9![Frontier logo]()
$133
This Kiwi.com deal was found by Cheapflights users on 9/10. 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.
Wed 9/308:10 pm -
Nonstop2h 29m
Mon 10/56:40 am -
1 stop8h 54m
Deal found 9/10![Frontier logo]()
$135
This Cheapflightsfares deal was found by Cheapflights users on 9/10. 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.
Wed 10/214:19 pm -
Nonstop2h 33m
Sat 10/314:09 pm -
Nonstop2h 05m
Deal found 9/10![Frontier logo]()
$136
This Super.com deal was found by Cheapflights users on 9/10. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/214:19 pm -
Nonstop2h 33m
Wed 10/2812:21 pm -
Nonstop2h 02m
Deal found 9/10![Frontier logo]()
$137
This Frontier deal was found by Cheapflights users on 9/9. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/168:00 pm -
Nonstop2h 39m
Mon 10/194:12 pm -
Nonstop2h 03m
Deal found 9/9![Frontier logo]()
$138
This Kiwi.com deal was found by Cheapflights users on 9/11. 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.
Sat 10/312:17 pm -
1 stop7h 16m
Wed 10/78:50 pm -
Nonstop2h 09m
Deal found 9/11![Frontier logo]()
$139
This Cheapflightsfares deal was found by Cheapflights users on 9/12. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/136:30 am -
Nonstop2h 56m
Sun 11/158:55 pm -
Nonstop2h 26m
Deal found 9/12![Frontier logo]()
$145
This Frontier deal was found by Cheapflights users on 9/8. 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.
Sat 10/176:30 am -
Nonstop2h 49m
Wed 10/288:55 pm -
Nonstop2h 26m
Deal found 9/8![Frontier logo]()
$160
Best flights from Illinois to ColoradoDiscover carefully curated flight deals from Illinois to Colorado that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 13, 2026.
Discover carefully curated flight deals from Illinois to Colorado that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 13, 2026.
This Delta deal was found by Cheapflights users on 9/10. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/92:33 pm -
1 stop6h 48m
Mon 12/146:16 pm -
1 stop4h 10m
Deal found 9/10![Delta logo]()
$197
This Southwest deal was found by Cheapflights users on 9/8. 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 1/288:30 am -
1 stop5h 10m
Mon 2/17:30 am -
Nonstop2h 15m
Deal found 9/8![Southwest logo]()
$235
This United Airlines deal was found by Cheapflights users on 9/8. 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.
Sat 10/39:03 am -
Nonstop2h 52m
Tue 10/62:55 pm -
1 stop5h 56m
Deal found 9/8![United Airlines logo]()
$303
This American Airlines deal was found by Cheapflights users on 9/7. 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.
Thu 10/225:00 am -
1 stop5h 37m
Sun 10/253:58 pm -
1 stop7h 01m
Deal found 9/7![American Airlines logo]()
$387
This Delta deal was found by Cheapflights users on 9/8. 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 12/27:08 am -
1 stop5h 51m
Sun 12/612:57 am -
1 stop6h 59m
Deal found 9/8![Delta logo]()
$197
This Alaska Airlines deal was found by Cheapflights users on 9/9. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/207:00 am -
2 stops16h 12m
Mon 10/266:59 pm -
1 stop17h 26m
Deal found 9/9![Alaska Airlines logo]()
$478
This Southwest deal was found by Cheapflights users on 9/8. 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 10/222:10 pm -
1 stop4h 35m
Mon 10/2611:35 am -
1 stop5h 10m
Deal found 9/8![Southwest logo]()
$249
This Southwest deal was found by Cheapflights users on 9/9. 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 1/227:45 pm -
Nonstop2h 45m
Tue 1/2611:20 am -
1 stop4h 10m
Deal found 9/9![Southwest logo]()
$249
This Southwest deal was found by Cheapflights users on 9/10. 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 10/89:50 pm -
Nonstop2h 25m
Thu 10/155:55 am -
1 stop5h 50m
Deal found 9/10![Southwest logo]()
$251
This United Airlines deal was found by Cheapflights users on 9/8. 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.
Mon 11/236:50 pm -
1 stop4h 54m
Sat 11/286:00 am -
1 stop5h 06m
Deal found 9/8![United Airlines logo]()
$307
This Delta deal was found by Cheapflights users on 9/9. 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.
Tue 1/129:30 am -
1 stop5h 33m
Mon 1/186:10 am -
1 stop4h 41m
Deal found 9/9![Delta logo]()
$282
This Southwest deal was found by Cheapflights users on 9/8. 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 11/41:20 pm -
1 stop5h 05m
Fri 11/64:20 pm -
1 stop5h 20m
Deal found 9/8![Southwest logo]()
$258
This United Airlines deal was found by Cheapflights users on 9/8. 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 10/204:20 pm -
1 stop5h 24m
Fri 10/2311:57 am -
Nonstop2h 45m
Deal found 9/8![United Airlines logo]()
$319
This Delta deal was found by Cheapflights users on 9/11. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/179:29 am -
1 stop6h 37m
Tue 10/206:20 am -
1 stop5h 27m
Deal found 9/11![Delta logo]()
$316
This Southwest deal was found by Cheapflights users on 9/10. 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.
Wed 11/45:45 pm -
Nonstop2h 40m
Sun 11/87:10 am -
Nonstop2h 20m
Deal found 9/10![Southwest logo]()
$262
This United Airlines deal was found by Cheapflights users on 9/12. 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 11/205:30 pm -
1 stop6h 14m
Mon 11/234:24 pm -
1 stop5h 34m
Deal found 9/12![United Airlines logo]()
$339
This Southwest deal was found by Cheapflights users on 9/10. 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.
Sat 10/176:15 am -
Nonstop2h 40m
Mon 10/198:55 pm -
Nonstop2h 25m
Deal found 9/10![Southwest logo]()
$262
This Delta deal was found by Cheapflights users on 9/12. 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.
Wed 10/216:20 am -
1 stop6h 44m
Thu 10/2212:59 am -
1 stop5h 42m
Deal found 9/12![Delta logo]()
$325
This United Airlines deal was found by Cheapflights users on 9/11. 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.
Sat 9/2610:48 am -
1 stop6h 34m
Sat 10/311:40 am -
1 stop6h 28m
Deal found 9/11![United Airlines logo]()
$339
This KAYAK deal was found by Cheapflights users on 9/11. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/293:00 pm -
1 stop5h 38m
Thu 10/19:03 am -
1 stop5h 57m
Deal found 9/11![American Airlines logo]()
$456
This Southwest deal was found by Cheapflights users on 9/8. 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 10/215:50 am -
2 stops6h 10m
Mon 10/265:25 pm -
1 stop4h 25m
Deal found 9/8![Southwest logo]()
$266
This Delta deal was found by Cheapflights users on 9/8. 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 10/208:29 am -
2 stops12h 47m
Fri 10/231:31 pm -
1 stop6h 07m
Deal found 9/8![Delta logo]()
$334
This Alaska Airlines deal was found by Cheapflights users on 9/8. 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 10/67:20 am -
2 stops16h 17m
Tue 10/136:59 pm -
1 stop17h 26m
Deal found 9/8![Alaska Airlines logo]()
$503
This United Airlines deal was found by Cheapflights users on 9/10. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/85:00 am -
1 stop4h 40m
Mon 10/126:03 pm -
1 stop4h 56m
Deal found 9/10![United Airlines logo]()
$357
This KAYAK deal was found by Cheapflights users on 9/9. 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.
Wed 9/1612:09 pm -
1 stop6h 33m
Thu 9/173:38 pm -
1 stop7h 21m
Deal found 9/9![American Airlines logo]()
$499
This Southwest deal was found by Cheapflights users on 9/8. 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 10/148:50 pm -
Nonstop2h 25m
Sun 10/186:20 am -
Nonstop2h 00m
Deal found 9/8![Southwest logo]()
$287
This Alaska Airlines deal was found by Cheapflights users on 9/11. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/107:20 am -
2 stops12h 05m
Mon 10/126:59 pm -
1 stop17h 26m
Deal found 9/11![Alaska Airlines logo]()
$518
This United Airlines deal was found by Cheapflights users on 9/10. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/102:28 pm -
1 stop6h 17m
Mon 10/126:00 am -
1 stop4h 52m
Deal found 9/10![United Airlines logo]()
$357
This Delta deal was found by Cheapflights users on 9/10. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 1/167:10 am -
2 stops11h 04m
Mon 1/181:40 pm -
1 stop6h 30m
Deal found 9/10![Delta logo]()
$362
This United Airlines deal was found by Cheapflights users on 9/11. 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.
Sat 11/144:39 pm -
Nonstop2h 31m
Tue 11/171:55 pm -
Nonstop2h 02m
Deal found 9/11![United Airlines logo]()
$357
Last-minute flights from Illinois to ColoradoDiscover last-minute flight deals from Illinois to Colorado. Data last updated September 13, 2026 and is based on user searches.
Discover last-minute flight deals from Illinois to Colorado. Data last updated September 13, 2026 and is based on user searches.
This Kiwi.com deal was found by Cheapflights users on 9/10. 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.
Wed 9/308:10 pm -
Nonstop2h 29m
Mon 10/56:40 am -
1 stop8h 54m
Deal found 9/10![Frontier logo]()
$135
This Frontier deal was found by Cheapflights users on 9/10. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/28:10 pm -
Nonstop2h 29m
Thu 10/86:30 am -
1 stop9h 28m
Deal found 9/10![Frontier logo]()
$141
This Kiwi.com deal was found by Cheapflights users on 9/11. 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.
Sat 10/312:17 pm -
1 stop7h 16m
Wed 10/78:50 pm -
Nonstop2h 09m
Deal found 9/11![Frontier logo]()
$139
This Cheapflightsfares deal was found by Cheapflights users on 9/7. 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 10/76:30 am -
Nonstop2h 45m
Fri 10/96:16 pm -
1 stop19h 09m
Deal found 9/7![Frontier logo]()
$161
This Frontier deal was found by Cheapflights users on 9/9. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/168:00 pm -
Nonstop2h 39m
Mon 10/194:12 pm -
Nonstop2h 03m
Deal found 9/9![Frontier logo]()
$138
This Kiwi.com deal was found by Cheapflights users on 9/9. 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.
Sat 10/177:42 pm -
Nonstop2h 27m
Tue 10/206:57 pm -
1 stop21h 43m
Deal found 9/9![Frontier logo]()
$127
This Frontier deal was found by Cheapflights users on 9/8. 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.
Sat 10/176:30 am -
Nonstop2h 49m
Wed 10/288:55 pm -
Nonstop2h 26m
Deal found 9/8![Frontier logo]()
$160
This FlightHub deal was found by Cheapflights users on 9/8. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/191:30 pm -
1 stop24h 18m
Sat 10/243:54 pm -
Nonstop2h 03m
Deal found 9/8![Frontier logo]()
$132
This Cheapflightsfares deal was found by Cheapflights users on 9/10. 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.
Wed 10/214:19 pm -
Nonstop2h 33m
Sat 10/314:09 pm -
Nonstop2h 05m
Deal found 9/10![Frontier logo]()
$136
This Super.com deal was found by Cheapflights users on 9/10. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/214:19 pm -
Nonstop2h 33m
Wed 10/2812:21 pm -
Nonstop2h 02m
Deal found 9/10![Frontier logo]()
$137
This Cheapflightsfares deal was found by Cheapflights users on 9/10. 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.
Fri 10/231:30 pm -
1 stop7h 20m
Mon 10/264:12 pm -
Nonstop2h 03m
Deal found 9/10![Frontier logo]()
$128
This Frontier deal was found by Cheapflights users on 9/9. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/284:18 pm -
Nonstop2h 30m
Sat 10/3110:40 am -
1 stop11h 36m
Deal found 9/9![Frontier logo]()
$133
One-way flights from Illinois to ColoradoSearch for one-way flight options from Illinois to Colorado. Find affordable one-way fares based on user searches. Data last updated September 13, 2026.
Search for one-way flight options from Illinois to Colorado. Find affordable one-way fares based on user searches. Data last updated September 13, 2026.
This CheapOair deal was found by Cheapflights users on 9/10. 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 11/15:24 pm -
Nonstop2h 20m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Allegiant Air logo]()
$68
This Mytrip deal was found by Cheapflights users on 9/11. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 10/36:30 am -
Nonstop2h 45m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/11![Frontier logo]()
$70
This Super.com deal was found by Cheapflights users on 9/10. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/612:17 pm -
1 stop7h 16m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Frontier logo]()
$78
This Cheapflightsfares deal was found by Cheapflights users on 9/11. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/52:29 pm -
1 stop7h 55m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/11![Frontier logo]()
$79
This Super.com deal was found by Cheapflights users on 9/11. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/72:29 pm -
1 stop7h 34m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/11![Frontier logo]()
$81
This Super.com deal was found by Cheapflights users on 9/10. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/224:30 pm -
1 stop24h 17m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Frontier logo]()
$84
This Cheapflightsfares deal was found by Cheapflights users on 9/10. 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 11/91:28 pm -
1 stop11h 21m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Frontier logo]()
$85
This Kiwi.com deal was found by Cheapflights users on 9/9. 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.
Mon 10/126:35 pm -
1 stop14h 31m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/9![Frontier logo]()
$87
This Southwest deal was found by Cheapflights users on 9/10. 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 10/129:50 pm -
Nonstop2h 25m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Southwest logo]()
$89
This Kiwi.com deal was found by Cheapflights users on 9/8. 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.
Fri 12/42:59 pm -
1 stop18h 27m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/8![Frontier logo]()
$90
This Super.com deal was found by Cheapflights users on 9/10. 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 Super.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/25:19 pm -
1 stop15h 33m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/10![Frontier logo]()
$91
This Super.com deal was found by Cheapflights users on 9/8. 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.
Tue 10/136:30 am -
Nonstop2h 49m
Wed 12/3112:00 am -
Nonstop0h 00m
Deal found 9/8![Frontier logo]()
$92
Find flight deals from Illinois to Colorado
Keep the following information in mind while searching for Illinois to Colorado flight deals. Data was last updated September 13, 2026.
Most accurate provider | FlightHub 3 stars |
|---|---|
Most trusted provider | FlightHub 3 stars |
Round-trip from | $127 (Kiwi.com) |
One-way from | $68 (CheapOair) |
Popular in | July |
Cheapest in | January |
Average price | $274 |
Good round-trip deal | $245 or less |
Good one-way deal | $141 or less |
Cheapflights Fare Finder
Customize your flight search to find flights from Illinois to Colorado 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 September 13, 2026.
Use the filters below to find and compare flights from Illinois to Colorado that are best for you.
Fly from
Fly to
Route
Depart
Return
Cheapest round-trip
Quickest round-trip
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Tue 10/20
6:10 pm-7:30 pm
Nonstop2h 20m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$89
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Wed 12/9
7:03 am-1:24 pm
1 stop7h 21m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$99
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Thu 12/10
6:03 am-10:08 am
1 stop5h 05m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$99
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Fri 10/9
9:50 pm-11:15 pm
Nonstop2h 25m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$106
ChicagoDenver
MDW Chicago Midway - DEN Denver Intl
MDWDEN
Chicago Midway
Mon 10/5
6:25 pm-8:05 pm
Nonstop2h 40m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$115
ChicagoDenver
MDW Chicago Midway - DEN Denver Intl
MDWDEN
Chicago Midway
Tue 9/29
8:55 am-1:30 pm
1 stop5h 35m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$125
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Tue 12/8
9:13 am-10:35 am
Nonstop2h 22m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$129
ChicagoDenver
ORD Chicago O'Hare Intl - DEN Denver Intl
ORDDEN
Chicago O'Hare Intl
Fri 10/9
5:00 am-6:39 am
Nonstop2h 39m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$129
ChicagoDenver
MDW Chicago Midway - DEN Denver Intl
MDWDEN
Chicago Midway
Fri 12/11
5:55 am-7:45 am
Nonstop2h 50m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$129
St. LouisDenver
STL Lambert-St Louis - DEN Denver Intl
STLDEN
Lambert-St Louis
Tue 10/6
2:35 pm-3:55 pm
Nonstop2h 20m
Denver Intl
Wed 12/31
12:00 am-1:00 am
Nonstop0h 00m
$139
Showing 1-10 of 60 resultsSorted by cheapest first
Best time to book a flight from Illinois to Colorado
Have a flexible travel schedule? Discover the best time to fly to Colorado from Illinois with our price prediction graph.
STL-DEN
PIA-DEN
ORD-DEN
MDW-DEN
ORD-COS
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.
Cheapflights Insights
Everything you need to know about your flight from Illinois to Colorado
USIL-USCO
STL-DEN
PIA-DEN
ORD-DEN
MDW-DEN
What is the cheapest month to book a flight from Illinois to Colorado?
Currently, November is the cheapest month in which you can book a flight from Illinois to Colorado (average of $252). Flying from Illinois to Colorado in June is currently the most expensive (average of $344). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.
What is the cheapest time of day to fly from IL to CO?
Find hourly flight availability from Illinois to Colorado. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 13, 2026.
It’s optimal to fly from Illinois to Colorado at noon. By choosing this option you can save up to 15% on the cost of your flight, compared to a flight in the evening.
Weekly flight availability from Illinois to Colorado
Explore weekly flight availability from Illinois to Colorado. 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 September 13, 2026.
The most flights from USIL to USCO are scheduled on a Friday (76 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (50 on average).
How much does it cost to fly round-trip from Illinois to Colorado?
Airfare is below average for this route at the moment.
Illinois to Colorado flights typically cost between $203 and $337 in November.The cheapest round-trip price found within the last 5 days was $145 on Frontier (Nov 13-Nov 15).
How far ahead should I book a flight from Illinois to Colorado?
Booking 84 days in advance of your planned departure date is, on average, the best time to get cheap flights from Illinois to Colorado. The general trend is that the closer you book to the departure date, the more expensive your flight will be.
What is the cheapest day to fly from Illinois to Colorado?
Use this chart to determine the cheapest time to fly round-trip from Illinois to Colorado. Price data was last updated on September 12, 2026.
Travelers seeking maximum savings on their Illinois to Colorado flight should consider departing on Monday at noon when fares are most often at their lowest. Monday mornings flights should be avoided if possible as fares are typically the most expensive at this time.
Reviews of airlines servicing Colorado
Get insights into the airlines that provide service to Colorado. 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 Colorado. Reviews last updated September 13, 2026.
Read reviews from past customers who have flown Southwest,United Airlines, andAllegiant Air from Illinois to Colorado. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Food
7.0
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Food
7.0
Boarding
8.1
Comfort
8.0
Crew
8.6
Entertainment
7.5
Overall
8.0
Reviews
1 / 20
2.0
MediocreThomas,Dec 2025
SEA - DEN
Related info for your journey
Find useful and relevant information for your journey from Illinois to Colorado. 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 Illinois to Colorado
See prices for flight routes from nearby airports that may be better suited for you.
Complete your trip
Complete your trip to Colorado by adding a car rental and/or hotel reservation to your travel itinerary.
Search flights from Illinois to Colorado by cabin class
Find flights from Illinois to Colorado, based on your preferred cabin class, be it economy, premium economy, business, or first class.
Illinois and Colorado flights
Browse other Illinois and Colorado flight options. Last updated on September 13, 2026.
Popular flight searches
Check out other popular destinations found by fellow travelers in 2026
Find a return flight route from Colorado
Find the right flight back to Illinois after your stay in Colorado
Illinois to Colorado flights
Consider these flights traveling from Illinois to Colorado.
Top 7 airlines flying from Illinois to Colorado
Discover the top 7 airlines that operate flights from Illinois to Colorado. 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 September 13, 2026.
| Airline | Cheapest | Average | Flexibility | On-time |
|---|---|---|---|---|
| Cheapest$71 | Average$185 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$74 | Average$277 | FlexibilityNo cancel fee | On-time88% | |
| Cheapest$105 | Average$341 | FlexibilityNo cancel fee | On-timeN/A | |
| Cheapest$145 | Average$223 | FlexibilityNo cancel fee | On-time62% | |
| Cheapest$151 | Average$366 | FlexibilityNo cancel fee | On-time63% | |
| Cheapest$156 | Average$411 | FlexibilityNo cancel fee | On-time71% | |
| Cheapest$173 | Average$415 | FlexibilityNo cancel fee | On-time69% |