$47 Find Cheap Flights from Illinois to Colorado

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Low seasonJanuary
High seasonJuly
Cheapest flight$47
Best time to beat the crowds with an average 14% drop in price.
Most popular time to fly with an average 6% increase in price.
Flight from Chicago Midway Airport to Denver

FAQs for booking flights from Illinois to Colorado

  • How does KAYAK find such low prices on flights from Illinois to Colorado?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from Illinois to Colorado.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Illinois to Colorado?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Illinois to Colorado is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from Illinois to Colorado?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly from Illinois to Colorado with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Illinois to Colorado?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying from Illinois to Colorado up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which is the cheapest airport to fly into in Colorado?

    Prices will differ depending on the departure airport, but generally, the cheapest airport to fly to in Colorado is Colorado Springs Airport (COS), with an average flight price of $155.

  • What is the cheapest day to fly to Colorado?

    Based on KAYAK data, the cheapest day to fly to Colorado is Thursday where round-trip tickets can be as cheap as $242. On the other hand, the most expensive day to fly is Sunday, where round-trip prices are $310 on average.

  • What is the cheapest time of day to fly to Colorado?

    The cheapest time of day to fly to Colorado is generally in the evening, when round-trip flights cost $172 on average. Morning departures are around 60% more expensive than evening flights, on average. The most expensive time of day to fly to Colorado is generally in the afternoon, which is peak travel time and where the average cost of a ticket is $317.

  • What is the cheapest flight to Colorado?

    The cheapest ticket to Colorado from Illinois found in the last 72 hours was to Denver, at $101 round-trip. The most popular route is Bloomington (BMI) to Denver (DEN) and the cheapest round-trip airline ticket found on this route in the last 72 hours was $101.

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

    The cheapest month for flights from Illinois to Colorado is November, when tickets cost $142 (return) on average. On the other hand, the most expensive months are December and January, when the average cost of round-trip tickets is $218 and $193 respectively.

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

    To get a below average price on the flight from Illinois to Colorado, you should book around 3 weeks before departure. For the absolute cheapest price, our data suggests you should book 5 weeks before departure.

  • How long is the flight to Colorado?

    An average nonstop flight from Illinois to Colorado takes 7h 53m, covering a distance of 924 miles. The shortest route is Peoria (PIA) to Denver (DEN) with an average flight time of 2h 16m.

  • What are the most popular destinations in Colorado?

    Based on KAYAK flight searches, the most popular destination is Denver (87% of total searches to Colorado). The next most popular destinations are Colorado Springs (5%) and Aspen (3%). Searches for flights to Grand Junction (2%), to Durango (1%) and to Montrose (1%) are also popular.

Top 5 airlines serving from Illinois to Colorado

Need help choosing which airline to fly with from Illinois to Colorado? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4294 reviews
8.0Comfort
8.2Boarding
7.6Entertainment
7.1Food
8.6Crew
Airline reviews

After a 3 hour layover in Denver my flight was delayed over 5 hours! No explanation; no assistance; no offer to provide compensation; no one at Southwest was willing to offer any assistance. 8 hours in the Denver airport - ridiculous!

2.0 MediocreAnonymous, Apr 2025MSY - DEN
Read more Southwest reviews

After a 3 hour layover in Denver my flight was delayed over 5 hours! No explanation; no assistance; no offer to provide compensation; no one at Southwest was willing to offer any assistance. 8 hours in the Denver airport - ridiculous!

My flight to Chicago left and landed early. My return flight left two minutes late and arrived 2 minutes late. My seat selections were ideal! There were no snacks going to Chicago and no snacks on the return trip. There are no charging outlets on board.

WiFi on the flight was not working. Thus, entertainment options were limited.

I really like open seating. I hate that I've heard this is going away. This is one of the unique things that makes Southwest my goto choice.

For the first time in a long time we had a flawless experience with Southwest. Both flights were early and no mechanical errors at all. We were shocked and pleasantly surprised 😮.

One of the crew performed a hilarious skit to accompany the standard instructions. Passengers enjoyed it so much they applauded at the end!

Excellent experience. WiFi worked on this leg of My trip

It was really nice! I appreciate the gate attendant allowing families with small children to board early on in the process… that was very helpful! The internet service didn’t work with the app I was trying to use even though I paid the $8… other than that it was great! Oh and I should’ve asked for the whole cranberry cocktail can. That cup was about 2 sips…

A bit expensive for the overall service; but the flight departed on time and arrived early.

I love no assigned seats and bags fly free. If Private Equity gets their way and forces Southwest to change they will be everyone else and I will stop being loyal to them. DON'T CHANGE YOUR BUSINESS MODEL!!!

The gate attendant let me walk right by her with a bag too big for the overhead compartment

Food choices were very limited. Taste of the dishes was average.

I liked all the informational texts. I always knew where to go and when .

Received an email the night before showing that there would be seatback entertainment on our flight. We get on and there was no seatback entertainment. And then it was a scramble to try to set up the iPads for the kids before takeoff so they could watch something for the four hour flight.

The reason I don’t fly United. No in seat entertainment for a long flight and inconsistent WiFi and entertainment available from my device.

It was a good flight. Nothing comes to mind about how it could have been better. It was a newer plane, seemed like a great upgrade from your older ones. Staff was very good as well.

The food for long haul was poor compared to Singapore airlines economy. Pasta plain with tomato sauce . Singapore airlines give me Hagen dash small ice cream cup it was great. The choices of dinner course Singapore air also much better The crew mostly friendly. The economy seat are as expected.

The plane was clean. The staff was excellent. The flight attendants were very good. Enjoyable flight. Overall. The seats in the back are too small but, will always be.

Flight was 3 1/2 hour delayed with no credit or meal vouchers

late departure due to some unspecified issue with ventilating the cabin. They got it running but it was FREEZING for the whole flight. I asked for a blanket but they didn't provide one. They could not turn up the heat. it was quite miserable.

Easiest flights I’ve ever taken. Plane was comfortable without overly crowded seating.

Terrible. Still have not received the refund from them. They sent it to some account that I don't even know. Spoke with costumer service and they are unable to help.

I didn’t like it at all. I miss my second flight because of the delay on Allegiant Air now I m stuck in MCO.

Good, but a bit late on take off after loading. Don't like charging for carry ons!

First time flying with them and will definitely fly again in the future. Crew was so nice and friendly, fought was seamless. They are simple planes, no entertainment, but it’s fine for a short flight or if you have personal devices Rates are competitive, and they did so well with keeping the flight on time after a tropical storm, where other airlines had delays and cancellations.

They boarded passengers that sat in the back of the plane first, making boarding very efficient.

I didn't even take this flight. My plans changed and I couldn't get ahold of customer service and the website kept breaking down during the attempt to change the flight. I wound up taking another airline entirely and eating the cost.

The worst flying experience ever 3 delays. No accommodations. Had to deboard the plane after being delayed.

Posted a 20minute delay but didn’t delay at all. Caused boarding issues and confusion. Also, didn’t release baggage. Took over an hour and 20 minutes to get luggage.

Flight was good, boarding was a breeze, flight attendants were friendly and professional. There was a medical issue with another passenger and the crew handled it in a calm and professional way.

Terrible. The flight was delayed two hours due to weather. Then when we got on the plane, the first pilot ended up timing out and we had to wait for a second pilot. Second pile came on board and we tax it out. Had to return back to the gate because of an unruly passenger. Then the copilot timed out. Had to wait for new copilot. Also had to wait for maintenance to check for fuel. Then found out the second pilot timed out and we had to wait for a third pilot. Was ready to go and then needed maintenance again for another issue. In the end, it was 2 o’clock in the morning when they announced that the flight couldn’t go because the third pilot and the second copilot had timed out.

I have long legs, my foot was out in the aisle and when a flight attendant came walking by and I didn't notice, instead of saying "excuse me" or anything like that, she kicked my foot. Extremely rude

Excellent! The gate agents were kind enough to rebook me on an earlier flight saving me from a 6 hour layover. Even my luggage made it despite the fact that the connection was technically too narrow. The flight itself was very comfortable, roomy, and clean. Plenty of space for my carryon items with plugs to charge my phone. After a long international flight of 14 hours, this was an excellent way to end my travels!

One of the best flights I’ve had. So smooth.

Great experience. Flight boarded easily. Departed early. Smooth flight. Great arrival in DC--almost no taxing! Almost direct to gate from runway. Crew was terrific. Same cookies and beverages in main cabin. I did not use the entertainment system on this flight.

Most of the delay was due to weather which is not what was at issue here. One delay was due to a missing flashlight and in the end the flashlight was actually found on the plane. The entertainment system is very limited. Live TV options offer only a few channels that are not very appealing. Boarding and deplaning are always difficult. It just takes too much time to get on and off the plane. On the plus side, I missed my connecting flight, but was easily able to book a later flight from the app while enroute.

You were more on time than United. I'm so over united delays.

The meals were mediocre and the alcohol selection was poor. I enjoyed the selection of movies and other entertainment.

I chatted with the captain before the flight, and similarly during the welcome announcement, he warned of a turbulent flight that may impact the in-flight service. However, once at altitude, he announced that the weather changed and he immediately turned off the seatbelt sign. But it appeared the cabin crew had already decided to take off this flight. They remained seated and then just chatted in the galley. The flight was fully catered, but only first class received service.

My flight attendant was attentive! The elderly person next to me was flatulent and the flight attendant could see that I was in distress and brought me some face masks

Seats are uncomfortable but price is good. Guess I can put up with misery for four hours.

The plane failed preflight inspection, so we sat there for 90 mins while they tried to fix it. Ultimately, everything was remedied and we made our connecting flight; instead of a 2 hour layover at the airport, we spent it waiting on the plane.

I loked walking out on the tarmac to board and no first class. I didn't like that they have no snacks or onboard wifi to bide your time.

The seats were extremely hard and uncomfortable. It was disappointing even for a budget airline.

Delayed each time on a round trip with no significant weather interference. Updates to flight times came after the fact. 30 min behind in boarding and board and phone still show an on time departure. Some mysterious extra 300 miles that came so surprising they had to fuel while we were already on board?

Our flight was canceled for no known reason. We weren’t told until we were checking in at 5:00 am. This was after our last flight with Frontier where we sat on the plane for three hours (not an exaggeration) before we took off because of a mechanical issue. We won’t be flying Frontier again.

Allowed me to chose my seat without extra charge (I purchased full-price ticket) and boarding was in group1. Didn't even serve water.

Stuck in Phoenix for two days, not even a hotel voucher offered.

Every day about it was very different all the boarding pass where all wrong l miss flight no refund all crazy

Flight got delayed for 3.5 hours, and for the first hour after the departure time there was no update from the gate folks...

Book cheap flights from Illinois to Colorado

Recent round-trip flight deals

7/31Thu
nonstopFrontier
2h 50mORD-DEN
8/3Sun
nonstopFrontier
2h 45mDEN-ORD
$94
8/10Sun
nonstopFrontier
2h 50mORD-DEN
8/12Tue
nonstopFrontier
2h 45mDEN-ORD
$104
7/25Fri
nonstopAllegiant Air
2h 20mPIA-DEN
8/1Fri
nonstopAllegiant Air
2h 03mDEN-PIA
$146
6/23Mon
nonstopAllegiant Air
2h 18mPIA-DEN
6/30Mon
nonstopAllegiant Air
2h 04mDEN-PIA
$147
5/28Wed
nonstopSouthwest
2h 45mORD-DEN
6/4Wed
nonstopSouthwest
2h 35mDEN-ORD
$151
6/10Tue
nonstopSouthwest
2h 50mMDW-DEN
6/11Wed
nonstopSouthwest
2h 20mDEN-MDW
$151
5/30Fri
nonstopAmerican Airlines
2h 48mORD-DEN
6/4Wed
nonstopAmerican Airlines
2h 32mDEN-ORD
$165
6/2Mon
nonstopAmerican Airlines
2h 41mORD-DEN
6/7Sat
nonstopAmerican Airlines
2h 40mDEN-ORD
$169
5/23Fri
nonstopUnited Airlines
2h 50mORD-DEN
5/27Tue
nonstopUnited Airlines
2h 35mDEN-ORD
$173
8/16Sat
nonstopUnited Airlines
2h 28mMLI-DEN
8/25Mon
nonstopUnited Airlines
2h 14mDEN-MLI
$209

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Recent one-way flight deals

7/11Fri
nonstopFrontier
2h 44mMDW-DEN
$47
7/19Sat
nonstopFrontier
2h 29mSTL-DEN
$48
6/10Tue
nonstopUnited Airlines
2h 48mORD-DEN
$76
7/30Wed
nonstopSouthwest
2h 35mMDW-DEN
$76
8/13Wed
1 stopSouthwest
5h 25mORD-DEN
$81
6/2Mon
nonstopUnited Airlines
2h 50mORD-DEN
$85
7/25Fri
nonstopAllegiant Air
2h 20mPIA-DEN
$103
7/21Mon
nonstopAllegiant Air
2h 20mPIA-DEN
$110
7/30Wed
nonstopAmerican Airlines
2h 44mORD-COS
$114
7/6Sun
1 stopAmerican Airlines
8h 21mORD-DEN
$129

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Last minute flights from Illinois to Colorado

Last minute flight, train and bus deals

5/5Mon
multi-stopFrontier
13h 39mSTL-DEN
5/7Wed
multi-stopFrontier
22h 36mDEN-STL
$178
5/5Mon
multi-stopFrontier
13h 39mSTL-DEN
5/11Sun
multi-stopFrontier
22h 36mDEN-STL
$187
5/2Fri
multi-stopFrontier
7h 05mSTL-DEN
5/10Sat
nonstopFrontier
2h 09mDEN-STL
$189
5/2Fri
nonstopAllegiant Air
2h 19mPIA-DEN
5/5Mon
nonstopAllegiant Air
2h 00mDEN-PIA
$283
5/5Mon
nonstopAmerican Airlines
2h 44mORD-DEN
5/10Sat
nonstopAmerican Airlines
2h 46mDEN-ORD
$357
5/5Mon
nonstopSouthwest
2h 45mMDW-DEN
5/10Sat
nonstopSouthwest
2h 30mDEN-MDW
$357
5/3Sat
multi-stopAmerican Airlines
9h 28mPIA-DEN
5/10Sat
multi-stopAmerican Airlines
4h 48mDEN-PIA
$369
5/3Sat
nonstopUnited Airlines
2h 40mPIA-DEN
5/10Sat
nonstopUnited Airlines
2h 22mDEN-PIA
$379
5/3Sat
multi-stopUnited Airlines
5h 05mPIA-DEN
5/10Sat
nonstopUnited Airlines
2h 22mDEN-PIA
$389
5/3Sat
multi-stopSouthwest
7h 00mORD-DEN
5/10Sat
nonstopSouthwest
2h 35mDEN-ORD
$459

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Everything you need to know for your flight to Colorado

Cabin class types available on flights to Illinois

Cabin classes available on flights to Illinois. Prices are the lowest found on KAYAK over the last 7 days. Price and availability is not guaranteed.

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