$92 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 8/11. 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, 0 bags

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These are the airlines KAYAK users have selected most often from within our search results in flight searches from Denver to Illinois.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Denver to Illinois.
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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
Chicago1 stop$181
Moline
Molinenonstop$279
Peoria
Peorianonstop$104
Bloomington
Bloomington1 stop$309
Champaign
Champaign1 stop$270
Springfield
Springfield1 stop$417
St. Louis
St. Louisnonstop$166
Decatur
Decatur1 stop$401
Chicago
Chicago1 stop$181
Moline
Molinenonstop$279
Peoria
Peorianonstop$104
Bloomington
Bloomington1 stop$309
Champaign
Champaign1 stop$270
Springfield
Springfield1 stop$417
St. Louis
St. Louisnonstop$166
Decatur
Decatur1 stop$401

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

Thu, Oct 29 - Sun, Nov 1
Allegiant Air Logo
10:20 am - 1:19 pm
DEN
-
PIA
1h 59mnonstop
Allegiant Air Logo
5:24 pm - 6:44 pm
PIA
-
DEN
2h 20mnonstop
$104Allegiant Air
Fri, Jul 24 - Tue, Jul 28
Frontier Logo
4:10 pm - 7:23 pm
DEN
-
STL
2h 13mnonstop
Frontier Logo
8:08 pm - 9:44 pm
STL
-
DEN
2h 36mnonstop
$166Frontier
Tue, Aug 18 - Sat, Aug 22
Southwest Logo
6:30 am - 9:50 am
DEN
-
MDW
2h 20mnonstop
Southwest Logo
2:05 pm - 3:35 pm
MDW
-
DEN
2h 30mnonstop
$183Southwest
Tue, Aug 18 - Sat, Aug 22
Southwest Logo
11:15 am - 5:00 pm
DEN
-
MDW
4h 45m
1 stop
Southwest Logo
6:00 pm - 7:40 pm
MDW
-
DEN
2h 40mnonstop
$189Southwest
Tue, Sep 22 - Wed, Sep 30
Delta Logo
6:00 am - 1:07 pm
DEN
-
MDW
6h 07m
1 stop
Delta Logo
9:49 am - 3:24 pm
MDW
-
DEN
6h 35m
1 stop
$197Delta
Tue, Sep 22 - Thu, Oct 1
Delta Logo
6:00 am - 1:07 pm
DEN
-
MDW
6h 07m
1 stop
Delta Logo
7:13 pm - 11:25 pm
MDW
-
DEN
5h 12m
1 stop
$204Delta
Sun, Jul 12 - Tue, Jul 14
American Airlines Logo
5:00 am - 11:55 am
DEN
-
PIA
5h 55m
1 stop
American Airlines Logo
6:58 pm - 12:17 am
PIA
-
DEN
6h 19m
1 stop
$239American Airlines
Fri, Jul 10 - Tue, Jul 14
United Airlines Logo
5:38 pm - 8:54 pm
DEN
-
MLI
2h 16mnonstop
United Airlines Logo
6:30 pm - 11:48 pm
MLI
-
DEN
6h 18m
1 stop
$279United Airlines
Fri, Jul 10 - Tue, Jul 14
American Airlines Logo
4:23 pm - 11:30 pm
DEN
-
MLI
6h 07m
1 stop
American Airlines Logo
6:50 pm - 12:17 am
MLI
-
DEN
6h 27m
1 stop
$289American Airlines
Wed, Aug 5 - Sun, Aug 9
United Airlines Logo
5:38 pm - 8:54 pm
DEN
-
MLI
2h 16mnonstop
United Airlines Logo
6:30 pm - 11:48 pm
MLI
-
DEN
6h 18m
1 stop
$291United Airlines
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.

How much is a round-trip flight from Denver to Illinois?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from Denver to Illinois departing in August.

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 5 days was to Peoria, at $130 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 5 days was $169.

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

The average price for all round-trip flights from Denver to Illinois depending on the time of departure, clicked by users on KAYAK in the last 2 weeks.

The cheapest time of day to fly to Illinois is generally at night, when round-trip flights cost $237 on average. Morning departures are around 7% 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 $535.

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 $338, 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 September, when tickets cost $226 (return) on average. On the other hand, the most expensive months are December and February, when the average cost of round-trip tickets is $432 and $354 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 Thursdays and avoid leaving on a Sunday, as it's usually the priciest day. When flying back from Illinois, Wednesday is the cheapest day to fly and Monday 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 41% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 12 weeks before departure.

Good to know

Low seasonFebruary
Cheapest flight$92
Best time to beat the crowds with an average 4% drop in price.
Most popular time to fly and prices are also 4% lower on average.
Flight from Denver to Chicago O'Hare 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 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 - 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.

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 $145 one-way - $287 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.
7.9
SouthwestOverall score based on 4237 reviews
8.0Comfort
8.6Crew
7.0Food
7.5Entertainment
8.1Boarding
Airline reviews

Flight was delayed over 3 hours. Planes were dirty. Staff indifferent. And they serve vegan pretzels as snacks.

2.0 MediocreMatthew, Jun 2026
CVG - MDW
Read more Southwest reviews

Flight was delayed over 3 hours. Planes were dirty. Staff indifferent. And they serve vegan pretzels as snacks.

It was great. The gate staff were very helpful in Portland when my son forgot his rolling bag and had to go back to get it just in time to make it on the plane. We really appreciate that. Great job!

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

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 planes staff was top tier. Everything went great and had a great flight home.

Destroyed my suitcase. Tired of talking about it. Cancelling my unite mileage plus account.

New plane was lovely. Crew customer service is always lax but expected. Kraft on time and arrived safely.

It was a short flight so I was expecting too much

Had a one hour delay due to mechanical issue. I didn’t think I’d be able to make my connecting flight, but they waited for me and greeted me when I arrived to help things run smooth.

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

Was great in general, try to respect time and excuses when slight changes have been made, appreciated!

Really hard landing... as in slammed into the runway then hit the brakes really hard ...

Every staff member was professional, friendly and courteous. The pizza twist was ok. It was warm but too much dough.

Wonderful in-seat entertainment with seatback screens and huge selection of quality movies. The ability to bluetooth connect headphones was amazing.

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.

The flight was delayed significantly and we sat on runway after landing for awhile. Best thing was the flight attendant, Jenny, in first class, who was very professional and attentive. She was excellent - the rest of the flight was not.

The flight attendants were extremely sourly and borderline rude. I did not feel appreciated as an AA customer once.

The flight from LA to Chicago was smooth and service was very good overall.

The Mario was so helpful and provided amazing customer service however l have being waiting for a callback for almost a week now and have not heard anything further after l informed them l wanted to change my date of traveling because of my hospital appointment even send them proof and l was unable to use manag your booking on their website is a bit frustrating and l would appreciate an update on My request as soon as possible. And have called them times without numbers no response

Awful, tons of delays, I got into Chicago multiple hours late meaning I hit the very traffic I tried so desperately to avoid. Just empty apologies from American Airlines text alerts. Trash behavior from a trash airline.

They lost my baggage and I am still struggling to the information and update

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.

As we approached Denver, we encountered quite a bit of turbulence. I know this can sometimes be the case as I frequently fly this route but not on American. My gripe: Usually a pilot or co-pilot alerts passengers to the possibility of turbulance ahead of time. This did not occur nor did he communiucate during what was a pretty rough ride.

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.

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 from Denver to Illinois

Information on your arrival and departure airports