Cheap flights from Colorado (CO) to Illinois (IL)

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How to find the cheapest flight from
Colorado to Illinois

All the information you need to plan the best null to ORD flight in 2021: compare Colorado to Illinois flight prices with the expected peak season, weather and rainfall in Illinois.
When is the cheapest time to fly from Colorado to Illinois (CO - IL)?

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.

How far in advance should I book a flight from Colorado to Illinois?

To save up to 11% on this flight, we recommend booking at least 20 days prior to travel. The price may fluctuate and will likely increase closer to your departure date. Users on Cheapflights have found tickets from Colorado to Illinois from $122 1-2 weeks out and tickets from $139 for flights departing within the next 72 hours.

What is the cheapest month to fly from Colorado to Illinois?

August is one of the best times of the year to fly to Illinois from Colorado. Prices for August average $133 per person but you can even find prices for as low as $35. The most expensive prices can be found in the month of December. Opting for a August flight can save you 60% on your journey compared to booking in August

Cheap flights from Colorado to Illinois in November, December 2021

The best prices found for Colorado to Illinois flights for November, December
7 Dec - 11 Dec
$72pp
DEN
Denver Intl
Frontier
Non-Stop
STL
Lambert-St Louis
STL
Lambert-St Louis
Frontier
Non-Stop
DEN
Denver Intl
7 Dec - 15 Dec
$78pp
DEN
Denver Intl
Frontier
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Frontier
Non-Stop
DEN
Denver Intl
1 Dec - 4 Dec
$79pp
DEN
Denver Intl
Frontier
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Frontier
Non-Stop
DEN
Denver Intl

Colorado to Illinois 2022 flight deals

Cheap flights to Illinois from Colorado found for next year
7 Dec - 11 Dec
$72pp
DEN
Denver Intl
Frontier
Non-Stop
STL
Lambert-St Louis
STL
Lambert-St Louis
Frontier
Non-Stop
DEN
Denver Intl
7 Dec - 15 Dec
$78pp
DEN
Denver Intl
Frontier
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Frontier
Non-Stop
DEN
Denver Intl
1 Dec - 4 Dec
$79pp
DEN
Denver Intl
Frontier
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Frontier
Non-Stop
DEN
Denver Intl

Non-stop flights to Illinois from Colorado

Save time with Colorado to Illinois direct flight deals
7 Dec - 11 Dec
$72pp
DEN
Denver Intl
Frontier
Non-Stop
STL
Lambert-St Louis
STL
Lambert-St Louis
Frontier
Non-Stop
DEN
Denver Intl
8 Dec - 11 Dec
$72pp
DEN
Denver Intl
Frontier
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Frontier
Non-Stop
DEN
Denver Intl
7 Dec - 15 Dec
$78pp
DEN
Denver Intl
Frontier
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Frontier
Non-Stop
DEN
Denver Intl

Last minute flights from Colorado to Illinois

Late deals on round-trip flights to Illinois from Colorado, departing today and this week
1 Dec - 4 Dec
$79pp
DEN
Denver Intl
Frontier
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Frontier
Non-Stop
DEN
Denver Intl
4 Dec - 4 Dec
$81pp
DEN
Denver Intl
Frontier
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Frontier
Non-Stop
DEN
Denver Intl
4 Dec - 4 Dec
$83pp
DEN
Denver Intl
Frontier
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Frontier
Non-Stop
DEN
Denver Intl

One-way flights to Illinois from Colorado

The cheapest one-way flights from Colorado to Illinois
2:00 am - 5:48 am
American Airlines
Nonstop
2h 48m
DEN - ORD
American Airlines
6:16 pm - 5:04 am
Spirit Airlines
1 Stop
9h 48m
DEN - ORD
Spirit Airlines
$66
mytrip.com
6:19 am - 9:27 am
Frontier
Nonstop
2h 08m
DEN - STL
Frontier
$67
Kiwi.com

Related info for your journey

Useful info, stats and facts about <span class="emphasized">Colorado</span> to <span class="emphasized">Illinois</span> flights.

Flight FAQs

From Colorado to Illinois

Which airlines flying from Colorado to Illinois have flexible cancellations due to COVID-19?

Some of the carriers operating flights from Colorado to Illinois that may be offering flexible cancellation policies are United Airlines, Frontier, and Spirit Airlines. Our site will let you filter for all airlines offering greater flexibility due to COVID-19.

Can I find flights from Colorado to Illinois for under $100 on Cheapflights?

Yes, there are multiple flights from Colorado to Illinois for under $100. The cheapest flight booked recently is on Frontier for just $72, but on average you can expect to pay $93.

Are there nonstop flights from Colorado to Illinois for under $100 on Cheapflights?

Cheapflights has at least 20 direct flights from Colorado to Illinois under $100. A good price for a nonstop flight from Colorado to Illinois is less than $94.

Are there last-minute flights available from Colorado to Illinois for under $100?

There are currently 20+ open flights from Colorado to Illinois within the next 7 days for less than $100.

What days are nonstop flights available from Colorado to Illinois?

Days when nonstop flights are available for this flight are: Sunday, Monday, Tuesday, Wednesday, Friday, Saturday.

How many flights depart from Colorado to Illinois on average per day?

Travelers can expect 73 flights from Colorado to Illinois on average per day.
Early Morning (Midnight to 6am) - 12% of flight departures
Morning (6am - Noon) - 52% of flight departures
Afternoon (Noon - 6pm) - 29% of flight departures
Evening (6pm - Midnight) - 7% of flight departures

How long is the flight from Colorado to Illinois?

Airlines like Frontier fly from Colorado to Illinois in about 2h 06m. The time it takes to get you to your destination is usually consistent. Colorado and Illinois are separated by a distance of 891 mi. Most flights are nonstop.

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 $43. However, be on the lookout for offers from Spirit Airlines and American Airlines, as they are both options that can get you from Colorado to Illinois for a low price.

COVID Restrictions

View COVID Travel Restrictions for Illinois (IL)

Do I need a COVID test to fly to Illinois from Colorado?

Information is based on travel restrictions for travel to Illinois within the United States

Most visitors from Colorado need to provide a negative COVID-19 test result and/or quarantine to enter Illinois.

COVID-19 testing requirements
Visitors from Colorado must present a negative RT-PCR (NAAT) or Antigen (quick-test) test taken 72 hours before departing to Illinois.

Quarantine requirements
Visitors from Colorado are not required to quarantine after entering Illinois.

Do I need a test to fly back to Colorado from Illinois?

Returning to Colorado from Illinois

COVID-19 testing requirements
Visitors from Illinois must present a negative RT-PCR (NAAT) or Antigen (quick-test) test taken 72 hours before departing to Colorado.

Quarantine requirements
Visitors from Illinois are not required to quarantine after entering Colorado.

Hide COVID Travel Restrictions for Illinois (IL)

Destination points for flights from Colorado to Illinois

Select to see more specific information for flights from Colorado to all places in Illinois.

Destination information for Illinois

Things to know before you go - useful duration and weather info for your trip from Colorado to Illinois.
Flight duration from Colorado to Illinois
2h 30m

Airports servicing

Colorado Springs (COS)
Denver (DEN)
Durango (DRO)
Vail Eagle County (EGE)
Loveland Northern Colorado (FNL)

Airports servicing

Bloomington (BMI)
Champaign (CMI)
Decatur (DEC)
Moline (MLI)
Marion (MWA)

Top 6 airlines flying from Colorado to Illinois

The chart below displays the airlines Cheapflights users traveling from Colorado to Illinois choose most often. Cheapest and average prices are based on aggregated data from the past 12 months.
Airline Cheapest Average Flexibility On-time COVID-19 safety
Frontier
$48 $155 No cancel fee 62%
United Airlines
$50 $425 No cancel fee 69%
Spirit Airlines
$53 $148 No cancel fee 65%
American Airlines
$73 $410 No cancel fee 71%
Delta
$82 $361 No cancel fee N/A
Southwest
$246 $409 No cancel fee 63%
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