$63 Find Cheap Flights from Denver to Illinois

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Denver to Illinois departing on 11/6. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy

KAYAK searches hundreds of travel sites at once for deals on flights to Illinois

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Denver to Illinois, as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Denver to Illinois, as well as popular online travel agencies
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Cheap Flights from Denver to Illinois

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Chicago
Chicagononstop$116
Moline
Molinenonstop$219
Peoria
Peorianonstop$108
Bloomington
Bloomington1 stop$373
Champaign
Champaign1 stop$465
Springfield
Springfield1 stop$387
Decatur
Decatur1 stop$329
St. Louis
St. Louisnonstop$96
Chicago
Chicagononstop$116
Moline
Molinenonstop$219
Peoria
Peorianonstop$108
Bloomington
Bloomington1 stop$373
Champaign
Champaign1 stop$465
Springfield
Springfield1 stop$387
Decatur
Decatur1 stop$329
St. Louis
St. Louisnonstop$96

Book Cheap Denver to Illinois Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Denver to Illinois that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Denver to Illinois

Fri, Dec 5 - Mon, Dec 8
Frontier Logo
6:50 am - 10:02 amDEN-STL
2h 12mnonstop
Frontier Logo
7:43 pm - 9:15 pmSTL-DEN
2h 32mnonstop
$96Frontier
Find Deal
Wed, Nov 12 - Fri, Nov 14
Frontier Logo
6:00 am - 9:07 amDEN-STL
2h 07mnonstop
Frontier Logo
7:45 pm - 9:13 pmSTL-DEN
2h 28mnonstop
$100Frontier
Find Deal
Fri, Oct 24 - Mon, Oct 27
Allegiant Air Logo
6:41 pm - 9:32 pmDEN-PIA
1h 51mnonstop
Allegiant Air Logo
9:59 am - 11:15 amPIA-DEN
2h 16mnonstop
$108Allegiant Air
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Fri, Oct 24 - Mon, Oct 27
Allegiant Air Logo
6:41 pm - 9:32 pmDEN-PIA
1h 51mnonstop
Allegiant Air Logo
9:59 am - 11:15 amPIA-DEN
2h 16mnonstop
$113Allegiant Air
Find Deal
Fri, Oct 10 - Tue, Oct 14
United Airlines Logo
8:45 pm - 11:58 pmDEN-STL
2h 13mnonstop
United Airlines Logo
1:40 pm - 3:00 pmSTL-DEN
2h 20mnonstop
$131United Airlines
Find Deal
Fri, Oct 10 - Mon, Oct 13
United Airlines Logo
8:45 pm - 11:58 pmDEN-STL
2h 13mnonstop
United Airlines Logo
5:15 am - 6:53 amSTL-DEN
2h 38mnonstop
$144United Airlines
Find Deal
Tue, Oct 7 - Tue, Oct 7
Southwest Logo
7:15 am - 10:35 amDEN-MDW
2h 20mnonstop
Southwest Logo
2:45 pm - 4:20 pmMDW-DEN
2h 35mnonstop
$157Southwest
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Sat, Oct 25 - Sun, Oct 26
Southwest Logo
12:10 pm - 5:10 pmDEN-STL
4h 00m1 stop
Southwest Logo
8:50 pm - 12:40 amSTL-DEN
4h 50m1 stop
$162Southwest
Find Deal
Wed, Oct 29 - Wed, Nov 5
American Airlines Logo
9:20 am - 6:02 pmDEN-MLI
7h 42m1 stop
American Airlines Logo
5:22 pm - 11:09 pmMLI-DEN
6h 47m1 stop
$230American Airlines
Find Deal
Sat, Oct 18 - Mon, Oct 20
American Airlines Logo
4:00 pm - 11:55 pmDEN-MLI
6h 55m1 stop
American Airlines Logo
5:26 pm - 11:41 pmMLI-DEN
7h 15m1 stop
$284American Airlines
Find Deal
Booking Insights

KAYAK's insights & trends for Denver to Illinois flights

Get data-powered insights and trends into flights from Denver to Illinois to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest Denver to Illinois flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest ticket to Illinois from Denver found in the last 72 hours was to Peoria, at $71 round-trip. The most popular route is from Denver (DEN) to Chicago O'Hare Intl Airport (ORD), and the cheapest round-trip airline ticket found on this route in the last 72 hours was $114.

Can I save money by flying with a layover from Denver to Illinois?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of $251, prices are generally cheapest when you fly direct.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Denver to Illinois, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Denver to Illinois is October, when tickets cost $169 (return) on average. On the other hand, the most expensive months are May and April, when the average cost of round-trip tickets is $229 and $218 respectively.

What’s the cheapest day of the week to fly from Denver to Illinois?

The average price of all round-trip flights from Denver to Illinois clicked on KAYAK for each day over the last 12 months.

If you are looking for a flight deal from Denver to Illinois, look for departures on Fridays and avoid leaving on a Sunday, as it's usually the priciest day. When flying back from Illinois, Saturday is the cheapest day to fly and Sunday is the most expensive.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Denver to Illinois, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from Denver to Illinois, you should book around 4 weeks before departure, which saves you about 36% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 5 weeks before departure.

Good to know

Low seasonFebruary
Cheapest flight$63
Best time to beat the crowds with an average 9% drop in price.
Most popular time to fly and prices are also 13% lower on average.
Flight from Denver to Chicago Midway Airport

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

Insights shared by verified travelers who flew the route from Denver to Illinois 
AdamFlew with SouthwestDEN-ORDOct 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 AirlinesDEN-ORDJan 2024
Big airport. Make sure you have enough time between flights for rest, eating, etc…

FAQs - booking Illinois flights

  • How does KAYAK find such low prices on flights from Denver 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 Denver to Illinois.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Denver 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 Denver 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 Denver 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 Denver 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 Denver to Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

  • 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 $192 on average. Morning departures are around 2% cheaper 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 $622.

Top tips for finding cheap flights to Illinois

  • Looking for a cheap flight? 25% of our users found tickets from Denver to the following destinations at these prices or less: Chicago $119 one-way - $207 round-trip

Reviews of the top 5 airlines serving from Denver to Illinois

 
See real verified KAYAK customer reviews for airlines flying from Denver to Illinois. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from Denver 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.
8.0
SouthwestOverall score based on 4242 reviews
7.5Entertainment
8.1Boarding
8.6Crew
7.0Food
8.0Comfort
Airline reviews

WiFi did not work. For as outrageous as these flights cost, when they’re advertised with certain services/ features they should be in working order

2.0 MediocreMike, Jul 2025DEN - BWI
Read more Southwest reviews

WiFi did not work. For as outrageous as these flights cost, when they’re advertised with certain services/ features they should be in working order

Worst experience I had on Southwest. Still better than most, but the seating was barely tolerable.

It was okay. The plane was delayed from earlier in the day, but they kept updating the departure time, sometimes later, sometimes earlier. That was stressful. Once we finally got on and took off, it was fine. I was supposed to have a connection in Chicago to Los Angeles, and the time for so late I was rebooked to arrive in LA 3 hours late. The departure time to Chicago later became early enough to have taken my original connection and arrive earlier but that wasn't an option.

Everything was on time. I was disappointed by the front section female, African American flight attendant. I did not see her name tag or would have identified by name not race. As passengers moved to the bathroom early in flight, she would say with a disdainful tone “I have to say the seat belt light is on” then go back to her book. Better trained flight attendants say something like be careful the seat belt light is on.

I would have liked to arrive on time - not 5 hours late!

1.5 hour delay, poor service, no compassion from the crew. Terrible experience

Our flight was diverted from being a non-stop to getting within 150 miles and requiring another plane. We heard 4 or 5 different versions from SW as to why we had to stop, then wait for a replacement plane. Five hour delay, weather did not come up as a single excuse.... communication was not clear and well explained. No one really took charge!

Flight was awfully bumpy and landing was a bit jolting. I was in the restroom when snacks and drinks were served and was not asked if i wanted any. I had to ask for water finally.

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.

It seems as though the provisions are even less. Although SWA used to be an economy Airline, that isn't really the case anymore. I paid over $700. for a round trip to Denver and I could have flown just about any airline for the price. The drinks are now in a 6-ounce cup and with ice I'm sure a can would fill more than 2 cups. However, I am very proud of SWA for using paper rather than continuing to contribute to the millions of plastic cups being used each day. I've thought of this fr many years and am so glad to see it come to fruition, if not by only SWA so far.

Impressed with the service despite turbulence because of the weather. Both flights arrived before their scheduled times.

Great experience…left a bit behind schedule but made up fir that in the air and landed 10 minutes early 😁

Electric plugs didn't work. Entertainment system wasn't working

The design of the light switch on the arm rest is ridiculous.

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

Overall, it was a good experience. Boarding was good and there was plenty of overhead bin space for everyone’s carryons (even when we boarded toward the end). Only improvement would be to offer trash service more regularly.

David went above and beyond to make our flight the best that it could be

No food service almost missed because of first flight delays

Had a hard time finding my assigned seat. No attendants to assist.

The negative was the wait at the airport coming back. I checked my bags in, an hour before boarding and I get the notification that my flight was delayed. Rather had gotten the notification while I was at the hotel. Then it was delayed 3 x’s. Ugh!

Don’t know they cancelled the flight day before I was to leave. They sent a email at 9:00 pm at night saying they cancelled. That is the smooth way to say we don’t want your business! I think they didn’t have enough people booking so they cancelled the flight! It’s all about the money anymore there is no honesty in business.

Any flight to ORD after about 2pm this summer has been challenging. Flight was delayed getting in (coming from ORD) and that led to it not leaving before a ground stop due to lightening before they could fuel the plane, and so forth. They made up some time but we were still late in arriving at ORD, and that led to missed connections.

Food was ok, but not as good as I have had before on AA.

Pretty good. The food was just mediocre, the boarding and crew were good.

My flight got switched and my prepaid bag didnt transfer over properly so I paid to check ANOTHER BAG. I was placed in a middle seat and it was just miserable. At least it was a bulkhead row so I had legroom. The flight just never seem3d to end

Was not able to watch most shows on the entertainment site. They would not load

On Wednesday, July 30 we were in mid flight from Manchester to Charlotte and we turned around because the right engine was malfunctioning. That was the last flight out of Manchester that night. I was rebooked for Thursday, which became a weather event Friday. There were no seats left on the flight from Manchester to Charlotte. Consequently I didn’t leave Manchester until Saturday morning and we flew to Chicago so to say the least my scheduled flight and return to Iowa was three days off and it messed with my business schedule. Consequently cash flow. I would like some sort of acknowledgment of this event.

Dreadful experience. Our flight was delayed more than 8 hours due to a maintenance issue and the assistance from rebooking was poor. I was travelling with a bad knee and needed assistance waited in one place more than 3 hours before someone came with a wheelchair. The woman next to me was a 91 year old great grandmother who had waited more than 4 hours. There were moments of support from the staff but it appeared as they were going against the direction of management. It was apathy, lack of ownership and dismissive responses with small moments of kindness and understanding typically from grey haired, female, veteran staff..

Couldn’t get the door on the plane to close leading to a nearly 2 hour delay. But, hey at least they didn’t cancel the flight.

The flight was fine and the crew awesome. The problem is ORD and AA. Computers went down, ORD fell apart and a 40 min flight turned into a 3 hour trip. Guess the answer is to not try and fly to ORD after noon. But, as I said, crew was awesome and did everything they could to lesson the flight time.

Crew was great. No entertainment and food and beverage was for purchase only, even water

It was canceled. The flight wasn’t rescheduled, everyone had to figure out their own new arrangements. They said we would get refunded our original fare and receive an additional $150. We received links for $100 only and they expired before we could activate them.

The plane had originated in Las Vegas at 6:30 in the morning and flew to Moline where we boarded. The flight left around 12:30 PM and there were no boxed snacks available and many of the alcoholic beverages were unavailable. I would find it hard to believe that that many of the passengers coming from Las Vegas at 6:30 in the morning, drank and ate that much of the items. I can only come to the conclusion that someone failed to stock the plane for the round-trip. This is a huge revenue failure for the airline and disappointment for the passengers. The flight crew did not seem happy to be there and did not engage with passengers. Allegiant you can do better.

They did not let my husband on the plane with our service animal at the last minute. Do NOT fly this airline with a service animal!

Tight! Seats are not designed for those of us who wear extra-large clothes.

The non-stop flight from Grand Rapids was excellent. I neither expected or needed a budget flight and Allegiant made the trip easy and for an affordable price, Arriving at the Mesa Airport (AZA) is a delight compared to the international airport. For our return flight, we were able to arrive 75 minutes before the flight, return the rental car, check our bag and make it to the gate in plenty of time. That would never happen at most airports.

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!

What I expected, nickeled and dined and a frontier flight attendant loudly complained about her job and lack of communication as she headed to the gate on her cell phone. Not professional.

Severe turbulence. Captain never came on to reassure passengers after things settled down.

I’m not gonna fly Frontier Airlines because booking is not an option. No water or food is for high price, not equipped for health emergency incompetent crew for emergency services. Cheap airline shows it is cheaper in all service categories. Boarding is the best of all airlines!

We were delayed three times ,and that destroyed my plans, and reservations

Very bad! No good service delayed my second connection flight

Frontier is terrible. Paid for exit row, not given exit row, refused to refund fee.

2 hour delay due to late plane, wrong size plane causing overbooking, and people getting off and on the plane after boarding was completed.

The worst. We never made our connection and they did absolutely nothing to help us at the airport.

I never got to experience the flight because they delayed my first flight and I missed this one. Then Frontier didn't want to help me rebook a flight to get me to my final destination.

The Boarding process in Denver was chaotic, and since the line was so long, we were lined up very far from the gate. If there were any announcements from the gate staff, we didn't hear them. The flight attendants were spectacular. The only negative part of the flight was sitting by a 2 1/2 year old who was unruly and unfortunately had parents that matched his behaviors. Also, the restaurants in Denver on the E concourse, they didn't have food (passengers could only order 1 item on the entire menu) or the restaurants had 12-14 people waiting for orders to be prepared and another 6 people waiting to order. If you have a layover in Denver and need to grab food, be prepared to visit the shops with pre-packaged sandwiches, or you can visit another concourse but it may take a while to transit throughout the airport.

Everything you need to know for your flight from Denver to Illinois

Information on your arrival and departure airports

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