$93 Find Cheap Flights from Colorado to Illinois

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Low seasonJanuary
Cheapest flight$95
Best time to beat the crowds with an average 5% drop in price.
Most popular time to fly and prices are also 5% lower on average.
Flight from Denver to Chicago O'Hare Airport

Flights from Colorado to Illinois: the best tips from KAYAK users

Insights shared by verified travelers who flew the route from Colorado to Illinois 
AdamFlew with Southwest
DEN
-
ORD
Oct 2024
Arriving T5 at ORD on Southwest is often a LONG walk, with no moving walkways going out, to baggage claim / pickup.
BrianFlew with United Airlines
DEN
-
ORD
Jan 2024
Big airport. Make sure you have enough time between flights for rest, eating, etc…

FAQs for booking flights from Colorado to Illinois

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

    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 Colorado to Illinois.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Colorado to Illinois 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 Colorado to Illinois?

    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 Colorado to Illinois 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 Colorado to Illinois?

    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 Colorado to Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • Which airlines fly most frequently to Illinois?

    Colorado and Illinois are connected by different airlines. The airlines that fly that route the most regularly are United Airlines (203 flights per week), Air Canada (149 flights per week), and American Airlines (81 flights per week).

  • How many airports are there in Illinois?

    There are 12 airports in Illinois. The busiest airport is Chicago O'Hare Airport (ORD), with 94% of all flights arriving there.

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

    Prices will differ depending on the departure airport, but generally, the cheapest airport to fly to in Illinois is Chicago Midway Airport (MDW), with an average flight price of $206.

  • What is the cheapest day to fly to Illinois?

    Based on KAYAK data, the cheapest day to fly to Illinois is Friday where round-trip tickets can be as cheap as $304. On the other hand, the most expensive day to fly is Sunday, where round-trip prices are $502 on average.

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

    The cheapest time of day to fly to Illinois is generally at night, when round-trip flights cost $230 on average. Morning departures are around 4% more expensive than evening flights, on average. The most expensive time of day to fly to Illinois is generally in the afternoon, which is peak travel time and where the average cost of a ticket is $538.

  • What is the cheapest flight to Illinois?

    The cheapest ticket to Illinois from Colorado found in the last 3 days was to Peoria, at $150 round-trip. The most popular route is Aspen (ASE) to Chicago O'Hare Intl Airport (ORD) and the cheapest round-trip airline ticket found on this route in the last 3 days was $167.

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

    The cheapest month for flights from Colorado to Illinois is November, when tickets cost $294 (return) on average. On the other hand, the most expensive months are September and February, when the average cost of round-trip tickets is $494 and $490 respectively.

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

    To get a below average price on the flight from Colorado to Illinois, you should book around 4 weeks before departure, which saves you about 45% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 10 weeks before departure.

  • How many cities have direct flights to Illinois?

    From Colorado, there are direct flights to Illinois from 4 cities. The city with the most direct flights is Denver, with 855 direct flights each week.

  • How many direct flights to Illinois are there each day?

    There are around 136 direct flights from within Colorado to Illinois every day. Most flights (58%) depart in the morning.

  • How many direct flights to Illinois are there each week?

    Each week there are around 952 direct flights from within Colorado to Illinois. The most common day for departures is Sunday, with 16% of flights taking off on this day.

  • How long is the flight to Illinois?

    An average nonstop flight from Colorado to Illinois takes 6h 22m, covering a distance of 927 miles. The shortest route is Denver (DEN) to St. Louis (STL) with an average flight time of 2h 00m.

  • How many long-haul flights are there to Illinois each week?

    There are not any long-haul (6-12 hour flight duration) or medium-haul (3-6 hour flight duration) flights to Illinois. Instead, there are 952 short-haul flights (up to 3 hour flight duration), with the most arriving from Denver.

  • What are the most popular destinations in Illinois?

    Based on KAYAK flight searches, the most popular destination is Chicago (84% of total searches to Illinois). The next most popular destinations are St. Louis (13%) and Moline (1%). Searches for flights to Peoria (1%), to Evansville (0%) and to Bloomington (0%) are also popular.

Reviews of the top 5 airlines serving from Colorado to Illinois

 
Need help choosing which airline to fly with from Colorado to Illinois? 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.
7.9
SouthwestOverall score based on 4276 reviews
8.1Boarding
7.0Food
8.6Crew
8.0Comfort
7.5Entertainment
Airline reviews

The first time I flew in the extra legroom section. It was difficult to notice a difference. I had bad luck with my neighbors. The crew was okay. Southwest has reduced the live TV options.

4.0 OkayAnonymous, May 2026
MDW - LAX
Read more Southwest reviews

The first time I flew in the extra legroom section. It was difficult to notice a difference. I had bad luck with my neighbors. The crew was okay. Southwest has reduced the live TV options.

The flight was smooth. The Southwest experience has degraded overall, but this one was okay.

No gluten free snacks. Seats felt worn or bare bones even though it was a new 737 MAX 8.

The checking experience in Orlando was terrible, almost missed the flight. Too many travelers and Southwest completely understaffed.

no service at all due to turbulence. they should've at least given us snacks, there were only 10 people on the entire flight.

This leg was much better, but we did have to have a 3 hour lay o er after coming from a very exhausting hiccup with our flight from BNA to Den

Southwest is kind of a slum airline. It’s gotten more expensive over the years for less and less service. I am a Southwest Chase Visa card holder and was forced to choose a seat in the 26th row in the middle seat. However my wife who is a rewards member but doesn’t hold a card or anything else, gets randomly assigned a normally paid seat in row 6! How does that work?

For the first time in a long time, the Wi-Fi actually worked the entire flight! The flight crew was amazing as usual.

Great flight. I didn't get a drink because I was asleep whole on the flight.

Love them will get a Southwest card to track my points and keep flying with them. My family and I were pleased with the services.

This flight is a quick way to get to Chicago, but a bit expensive.

O’hsre taxi and deboarding took 40 minutes. Needed 20 minutes extra time between connecting flights to avoid running through terminal.

Standard flight with a drinks and a snack- overall very quick flight. The flight attendants were very strict, bordered on rude.

Delayed - weather wasn't bad at either end. Also sat on tarmac in ORD.

boarded early to only find out that flight would sit at gate for 45 min to an hour. Landed in chicago and sat on runway for over an hour before got to gate. Total delay was extensive for a 45 min flight door to door.

The flight was significantly delayed. The inbound flight from EWR was delayed departing because of mechanical problems. My original departure from CLT was 5:28 pm but due to the delay of the inbound flight, after arrival, deplaning, cleaning, boarding, we did not push back from the gate until 9:00 pm. Once in the air, the flight was smooth and what was originally supposed to be an arrival in ORD at 7:30 pm local time turned out to be 9:35 pm.

The flight I was supposed to be on was supposed to take off at 1:50 from State College. It was delayed over and over and over again until somehow I had to rebook on a flight that was supposed to have left State College at 8 am that morning but didn't end up taking off until almost 6 pm. Not only was this completely unacceptable, the "token from United" was a 15 dollar meal voucher that has to be used by today. I would personally like some miles added to my account for this inconvenience. I was in transit for 8 hours from the time I arrive at State College Aiport to when I got home. I was supposed to be home at 3 pm and I returned at 8 pm. Unacceptable. I have not been on an on Time united flight in nearly 5 years.

newer aircraft, ability to connect my headset via blue tooth for entertainment.

Very comfortable flight, snacks and drinks were good, good communication from crew. Could have used a little more information on timing of boarding for group 5

Great flight. Got to watch a movie. Smooth flight and early arrival at ORD.

Seats were very uncomfortable and being charged for snacks and water.........

Allegiant actually impressed me, original inbound flight from PBG was so late they gave us a bird inbound from Des Moines and only left 1h late and gained 40 minutes back in the air. Comfortable flight with no frills but no complaints.

Flight was delayed. Crew was good but hot coffee was not available.

Great. No choice for n/a. No food or entertainment options

No food is available without purchasing it and there is no in-flight entertainment. Both of these are OK because we got an inexpensive flight from Allegiant and, otherwise, our experience was excellent.

just had water and there was plenty of leg & seat room. But then i don't weight 220#s!!

Not totally their fault- screaming kids that had zero parent intervention.

It was cold on the flight. The crew was very pleasant. I didn't order any food. We were delayed due to Captain waiting on maintenance log. He kept us informed though. The flight itself was smooth. I would definitely fly with Allegiant again!

I had a fantastic experience with Allegiant. I had wheelchair assistance and they helped me find my luggage and brought me to my car. Even loaded my luggage. Wonderful service!! Thank you Allegiant!

Superb. Staff great. Great flight. As with other airlines, seating too tight and restrictive.

Requested early boarding to disinfect seat, tray table, etc. before general boarding. Instructed to board after wheelchair passengers. Waited on jet bridge behind 12 wheelchair passengers. Stopped immediately after entering plane to wait for gate agent in rear of plane cleaning a seat that was wet, got to my row and found both seats adjacent to mine already occupied, with the lack of room making it impossible for me to clean my own space and defeating the purpose of my boarding early. Cleaned the armrests and tray table as best I could.

The wifi experience is awful. I had to try again and again, taking over 30 minutes, to connect to the wifi. I had to watch the same two ads over and over until I was finally successful. Once connected, it was anything but "high speed" and disconnected at least three times during the flight.

It was good, the staff was great, and the food, was as usual, tea and biscuit. Bathroom was clean, and the plane was clean as well.

Very good I can’t complain one bit. Thank you American Airlines for making my flight enjoyable and safe!

The staff and service on American Airlines were truly outstanding. I had requested wheelchair assistance for my mother due to her knee issues, and the team went above and beyond every step of the way—from boarding in Boston to our arrival in Chicago. Their care, professionalism, and attentiveness made the entire experience smooth and stress-free. I’m very grateful for the support they provided.

The new planes (American Eagle) are beautiful and especially comfortable. The flight attendants are consistently professional and courteous. And, while it may seem inconsequential, the new liquid tube of coffee creamer—in contrast to the powdered coffee creamer—makes all the difference in a cup of coffee.

Boarding was quick and efficient. We arrived at our destination early.

I'm not sure American is capable of on-time arrivals and departures. When you land at ORD, you almost always get held on the tarmac because your gate is still occupied. I may have missed my connection, but that ended up up being significantly delayed as well. Once again, I finally got home well after midnight.

Crew at the gate was very crabby and not at all polite. The plane was very hot the entire flight. And the seat cushion was very worn out.

The staff are very, very professional. It's what flying should feel like.

There weren't enough employees at check in took awhile to get bags checked. There wasn't a wheel chair for me, I was sent to someone who turns out to work for a different airline, if My flight hadn't been delayed I probably would have missed my flight as it was, by the time I arrived at my gate, they started boarding in about 15 minutes. I don't know who took me to my gate, definitely was not the normal people who take passengers to the gate. I'm guessing she may have been in a management position. I wish I knew her name, she went beyond to help me. With that said everyone was kind, and were doing the best they could. So, I choose to say it was an Adventure, stressful start, but good. In the end went well. The situation was not only difficult for passengers but the employee's.

The staff at the check in counter was so rude. Made you feel Incompetent

Frontier scheduled a 40 minute connection in DEN. What they failed to mention was that they “close the doors” 20 mins prior to departure, which means you only have 20 mins. Not enough time. Possibly against DOT regulations. Filing complaint.

Flight was scheduled at 9:40pm. Got delayed to 10 am, the next day. crazy

The bag check, flight check-in, and onboard experience convinced my wife and me that we will actively go out of our way to avoid flying Frontier Airlines in the future. At bag check, we were informed that check-in could only be completed via the Frontier mobile app. Unfortunately, the app was extremely frustrating—sending us through repetitive, confusing loops that repeatedly forced us to decline add-on services with nearly every click. While most airline apps upsell, this one felt intentionally exhausting. As the process dragged on, we became genuinely concerned that my phone battery would die before check-in could be completed. We approached the bag check staff—who were standing together talking—and explained both our frustration and our predicament. They laughed. Later, my wife described the interaction as “gaslighting,” which felt accurate. We were then informed it would cost $25 per person simply to have our boarding passes printed. From that point forward, the tone of the experience was consistently hostile. The bag check employees were condescending and combative, behaving more like bullies than customer service staff. Unfortunately, that same attitude continued onboard. One flight attendant argued with me when I attempted to stow my backpack in the overhead bin. I explained that we had each paid $75 to check our bags specifically so we would not need to use carry-on space and could have adequate legroom. She demanded to see my ticket, pointed out that it said “no carry-on”—which I acknowledged—and I reiterated that this was precisely why we paid to check our bags. Her response was, “I don’t make the rules.” She then walked away, but not before asking if I “truly wanted to fly back to Chicago today?”—an unnecessary and unmistakable threat. It is also worth noting that despite booking our tickets together in the same transaction, we were not seated together. Upon our return to Chicago—where we could once again sit together—we compared onboard experiences. We both remarked on how unhappy the flight attendants appeared and how each of us was separately asked whether we would like to purchase a beverage. We declined. At no point was water mentioned as an option, leaving us with the clear impression that even water came at a cost—or that complimentary water, if available at all, was deliberately left unmentioned. Overall, the experience was shocking and deeply disappointing, but it was also a profound learning experience—one we will not forget and will not repeat. -Steve

Plane was hot and miserable and the crew was rude!

12 hour delay required getting on and off plane 3 times - would have at least liked to have been offered a snack or drink

They didn’t offer a water, even after I asked

They switched our terminal 3 times and we were delayed for four plus hours!!!

It was an early flight and most people napped/slept and the crew let us which was nice.

Everything you need to know for your flight to Illinois

Cabin class types available on flights to Colorado

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