Illinois

$46+ Cheap flights from Colorado to Illinois

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 2/10. Fares are subject to change and may not be available on all flights or dates of travel.
DEN — ORD
Dec 27 — Jan 31
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Cheap flight deals from Colorado to Illinois

Discover tips and strategies to find the most affordable flight options for your journey from Colorado (USCO) to Illinois (USIL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated December 22, 2024.

Round-trip from

$78
(Cheapflightsfares)

One-way from

$49
(Cheapflightsfares)
From Colorado to Illinois
One-way flight from Colorado to Illinois

Find flight deals from Colorado to Illinois

Cheapest flights from Colorado to Illinois
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 December 22, 2024.

This Trip.com deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” 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.
Tue 12/319:47 amDEN - ORD
Nonstop2h 33mFrontier
Sat 1/46:10 amORD - DEN
1 stop26h 10mFrontier
Deal found 12/21$115
This Cheapflightsfares deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” 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 12/3111:04 pmDEN - MDW
1 stop8h 17mFrontier
Mon 1/610:04 pmMDW - DEN
Nonstop2h 53mFrontier
Deal found 12/21$166
This Cheapflightsfares deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” 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 12/266:06 pmDEN - STL
Nonstop2h 13mFrontier
Sat 1/257:09 pmSTL - DEN
Nonstop2h 28mFrontier
Deal found 12/21$193
This Southwest deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” 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 12/315:20 pmDEN - MDW
Nonstop2h 20mSouthwest
Mon 1/62:25 pmMDW - DEN
1 stop4h 25mSouthwest
Deal found 12/21$202
This Mytrip deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 12/319:47 amDEN - ORD
Nonstop2h 33mMultiple Airlines
Fri 1/311:53 amORD - DEN
1 stop6h 17mMultiple Airlines
Deal found 12/21$222
This Delta deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” 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 12/3012:20 amDEN - ORD
1 stop8h 01mDelta
Mon 1/611:50 amORD - DEN
1 stop6h 13mDelta
Deal found 12/21$226
This Delta deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” 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 12/3012:20 amDEN - MDW
1 stop7h 30mDelta
Mon 1/61:26 pmMDW - DEN
1 stop7h 59mDelta
Deal found 12/21$226
This Southwest deal was found by Cheapflights users on 12/20. Clicking the “Pick Dates” 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 12/317:05 amDEN - ORD
Nonstop2h 40mSouthwest
Sat 1/47:30 amORD - DEN
2 stops12h 40mSouthwest
Deal found 12/20$287
This Sun Country Air deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” 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.
Mon 12/306:50 pmDEN - ORD
1 stop21h 48mSun Country Air
Sun 1/58:03 pmORD - DEN
1 stop22h 27mSun Country Air
Deal found 12/21$328
This United Airlines deal was found by Cheapflights users on 12/21. Clicking the “Pick Dates” 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 12/281:28 pmDEN - MLI
1 stop6h 35mUnited Airlines
Thu 1/25:39 pmMLI - DEN
1 stop6h 55mUnited Airlines
Deal found 12/21$368
This American Airlines deal was found by Cheapflights users on 12/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/2912:36 pmMTJ - ORD
1 stop5h 42mAmerican Airlines
Sun 1/56:00 amORD - MTJ
1 stop9h 00mAmerican Airlines
Deal found 12/22$378
This United Airlines deal was found by Cheapflights users on 12/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/2912:55 pmMTJ - ORD
Nonstop2h 55mUnited Airlines
Sun 1/59:25 amORD - MTJ
Nonstop3h 26mUnited Airlines
Deal found 12/22$439

Find flights from Colorado to Illinois within your budget

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 2,558,603 searches. Data last updated December 22, 2024.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Sat 4/12

6:00 am-9:06 am

Nonstop2h 06m

Lambert-St Louis

Wed 4/16

6:51 pm-8:22 pm

Nonstop2h 31m

$78

DenverChicago

DEN - ORD

DENORD

Denver Intl

Mon 2/10

7:50 am-3:00 pm

1 stop6h 10m

Chicago O'Hare Intl

Wed 2/12

6:50 am-8:53 am

Nonstop3h 03m

$82

DenverChicago

DEN - MDW

DENMDW

Denver Intl

Tue 1/7

8:55 pm-12:13 am

Nonstop2h 18m

Chicago Midway

Mon 1/13

7:15 am-9:05 am

Nonstop2h 50m

$82

DenverPeoria

DEN - PIA

DENPIA

Denver Intl

Fri 2/14

5:35 pm-8:34 pm

Nonstop1h 59m

Greater Peoria

Fri 2/21

3:14 pm-4:45 pm

Nonstop2h 31m

$84

DenverChicago

DEN - ORD

DENORD

Denver Intl

Sat 1/25

1:00 pm-4:35 pm

Nonstop2h 35m

Chicago O'Hare Intl

Sat 1/25

5:35 pm-7:16 pm

Nonstop2h 41m

$134

DenverChicago

DEN - ORD

DENORD

Denver Intl

Sat 1/18

3:55 pm-7:31 pm

Nonstop2h 36m

Chicago O'Hare Intl

Sat 1/25

4:08 pm-5:59 pm

Nonstop2h 51m

$149

DenverChicago

DEN - MDW

DENMDW

Denver Intl

Thu 1/23

2:25 pm-5:40 pm

Nonstop2h 15m

Chicago Midway

Sat 1/25

7:20 pm-9:10 pm

Nonstop2h 50m

$168

DenverChicago

DEN - ORD

DENORD

Denver Intl

Sat 2/15

6:20 am-10:00 am

Nonstop2h 40m

Chicago O'Hare Intl

Sun 2/16

4:20 pm-6:10 pm

Nonstop2h 50m

$173

DenverSt. Louis

DEN - STL

DENSTL

Denver Intl

Sat 1/11

7:21 pm-11:27 pm

1 stop27h 06m

Lambert-St Louis

Mon 1/13

12:15 pm-10:07 am

2 stops22h 52m

$174

DenverChicago

DEN - ORD

DENORD

Denver Intl

Wed 4/9

9:08 pm-12:42 am

Nonstop2h 34m

Chicago O'Hare Intl

Sun 4/13

9:15 pm-5:09 pm

1 stop20h 54m

$200

Flights are sorted by cheapest round-trip flights first.

Deals found on 12/21

Showing 1-10 of 60 results
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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.
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.

Travel insights for flights from Colorado to Illinois

Get recent, data-driven insights about flights from Colorado to Illinois including ideal travel times, pricing trends, and more.

What is the cheapest month to book a flight from Colorado to Illinois?

Currently, August is the cheapest month in which you can book a flight from Colorado to Illinois (average of $245). Flying from Colorado to Illinois in March is currently the most expensive (average of $317). 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 December 22, 2024.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Colorado to Illinois as you normally would.

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 December 22, 2024.

The most flights from USCO to USIL are scheduled on a Sunday (56 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (17 on average).

Rainfall in Illinois by month

Plan your trip to Illinois by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Illinois ranges from 1.7 - 4.9 inches per month. August is typically the wettest month, when rainfall can reach 4.9 in. January is typically the driest time to visit Illinois when rainfall is around 1.7 in.

Temperature in Illinois by month

Plan your trip to Illinois by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Illinois, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 73.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 23.0 F).

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 December 22, 2024.
Read through reviews of airlines operating flights from Colorado to Illinois, such as Southwest, Delta and American Airlines. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
8.1
Very good
4,804 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Food

7.2

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

8.1
Very good
4,804 reviews
8.1
Very good
4,804 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Food

7.2

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

8.0
Very good
9,537 reviews
8.1
Very good
4,804 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Food

7.2

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

8.0
Very good
8,594 reviews
8.1
Very good
4,804 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Food

7.2

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

7.4
Good
9,028 reviews
8.1
Very good
4,804 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Food

7.2

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

7.4
Good
823 reviews
8.1
Very good
4,804 reviews

Comfort

8.1

Boarding

8.2

Crew

8.7

Overall

8.1

Entertainment

7.7

Food

7.2

Reviews

1 / 10

We BARELY made the connection and when we got onboard we were treated like disobedient children who should have arrived earlier because we had to ask other passengers to move so we could sit with our kids. The flight attendants on the first flight were nice but the second one, they were snippy and fairly rude.

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.
  • What are the cheapest airlines to fly from Colorado to Illinois one-way?

    The cheapest airline one-way is Frontier, with whom users have recently found tickets for as low as $49. However, be on the lookout for offers from United Airlines and Allegiant Air, as they are both options that can get you from Colorado to Illinois for a low price.

  • Can I find deals for flights from Colorado to Illinois that include hotel bookings?

    Yes. In addition to deals on Colorado to Illinois flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Colorado to Illinois?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Colorado to Illinois.

  • Can I find deals for business class flights from Colorado to Illinois?

    Yes. Cheapflights offers flight deals from Colorado to Illinois by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Colorado to Illinois?

    Currently, August is the cheapest month in which you can book a flight from Colorado to Illinois (average of $245). Flying from Colorado to Illinois in March is currently the most expensive (average of $317). 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.

See more FAQs

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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.

Top 5 airlines flying from Colorado to Illinois

Discover the top 5 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 2,558,603 searches. Data last updated December 22, 2024.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$39Average$144FlexibilityNo cancel feeOn-time62%
Allegiant AirCheapest$90Average$166FlexibilityNo cancel feeOn-time88%
American AirlinesCheapest$139Average$461FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$142Average$446FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$143Average$322FlexibilityNo cancel feeOn-time63%
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