$43 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 4/25. 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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Flight Deals

Cheap Flights from Denver to Illinois

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Chicago
Chicagononstop$174
Moline
Moline1 stop$189
Peoria
Peoria1 stop$189
Bloomington
Bloomington1 stop$269
Champaign
Champaign1 stop$238
Springfield
Springfield1 stop$397
St. Louis
St. Louisnonstop$95
Decatur
Decatur1 stop$374
Chicago
Chicagononstop$174
Moline
Moline1 stop$189
Peoria
Peoria1 stop$189
Bloomington
Bloomington1 stop$269
Champaign
Champaign1 stop$238
Springfield
Springfield1 stop$397
St. Louis
St. Louisnonstop$95
Decatur
Decatur1 stop$374

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

Sat, Apr 11 - Mon, Apr 13
Frontier Logo
6:40 am - 9:48 am
DEN
-
STL
2h 08mnonstop
Frontier Logo
8:19 pm - 9:52 pm
STL
-
DEN
2h 33mnonstop
$95Frontier
Thu, Apr 16 - Sat, Apr 18
Frontier Logo
4:09 pm - 7:21 pm
DEN
-
STL
2h 12mnonstop
Frontier Logo
8:17 pm - 9:50 pm
STL
-
DEN
2h 33mnonstop
$99Frontier
Wed, Apr 1 - Mon, Apr 6
Frontier Logo
6:40 am - 9:48 am
DEN
-
STL
2h 08mnonstop
Frontier Logo
8:19 pm - 9:52 pm
STL
-
DEN
2h 33mnonstop
$105Frontier
Wed, Apr 8 - Wed, Apr 15
Southwest Logo
5:55 pm - 9:30 pm
DEN
-
MDW
2h 35mnonstop
Southwest Logo
6:30 am - 8:10 am
MDW
-
DEN
2h 40mnonstop
$185Southwest
Wed, Apr 8 - Sat, Apr 11
American Airlines Logo
5:30 am - 11:42 am
DEN
-
PIA
5h 12m
1 stop
American Airlines Logo
12:12 pm - 5:39 pm
PIA
-
DEN
6h 27m
1 stop
$189American Airlines
Thu, Apr 9 - Sat, Apr 11
American Airlines Logo
6:19 am - 12:21 pm
DEN
-
MLI
5h 02m
1 stop
American Airlines Logo
3:48 pm - 9:59 pm
MLI
-
DEN
7h 11m
1 stop
$189American Airlines
Thu, Apr 9 - Thu, Apr 16
United Airlines Logo
5:55 pm - 9:19 pm
DEN
-
PIA
2h 24mnonstop
United Airlines Logo
8:50 am - 10:33 am
PIA
-
DEN
2h 43mnonstop
$249United Airlines
Thu, Apr 9 - Sat, Apr 11
United Airlines Logo
6:10 pm - 9:32 pm
DEN
-
MLI
2h 22mnonstop
United Airlines Logo
8:54 am - 10:33 am
MLI
-
DEN
2h 39mnonstop
$249United Airlines
Wed, Apr 8 - Mon, Apr 13
Multiple Airlines Logo
7:05 pm - 11:29 am
DEN
-
MLI
15h 24m
1 stop
Multiple Airlines Logo
9:55 pm - 9:43 am
MLI
-
DEN
12h 48m
1 stop
$253Multiple Airlines
Mon, Apr 6 - Fri, Apr 10
Multiple Airlines Logo
9:25 am - 7:06 pm
DEN
-
EVV
8h 41m
1 stop
Multiple Airlines Logo
7:53 am - 11:08 pm
EVV
-
DEN
16h 15m
1 stop
$322Multiple 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.

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 Chicago, at $172 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 $172.

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 $208 on average. Morning departures are around 2% 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 $551.

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 $327, 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 August, when tickets cost $195 (return) on average. On the other hand, the most expensive months are March and November, when the average cost of round-trip tickets is $275 and $254 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, Saturday 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 43% 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$43
Best time to beat the crowds but there is an average 12% increase in price.
Most popular time to fly and prices are also 4% lower on average.
Flight from Denver to St. Louis

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 $158 one-way - $263 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 4318 reviews
8.1Boarding
8.0Comfort
7.5Entertainment
7.0Food
8.6Crew
Airline reviews

WiFi was not working and didn’t have a beverage service

8.0 ExcellentNick, Mar 2026
BOS - MDW
Read more Southwest reviews

WiFi was not working and didn’t have a beverage service

My flight from Denver to Minneapolis was excellent. My flight from Minneapolis to Denver was one of the worst I flights I have ever experienced. I had a window seat, the gentleman in the middle seat was morbidly obese and SW should have made him purchase two seats. His elbow dug into my arm most of the way even after I asked to please be careful. I was literally squashed between the him and the window with no wiggle room. The plane was full so it was not possible to ask for a different seat. I realize I should have complained to the flight attendant but I didn't feel anything could be done to rectify the situation. I fly SW often, I will continue to do so as this was my first negative experience.

All good except once again bags took an hour at Midway Airport Happens all the time. Ridiculous

Everything went smoothly and we even arrived a little bit early.

The seats were comfortable, and the boarding process was pretty smooth.

It was rough. The staff was unprofessional, the choice of on board drinks terrible, it was cramped in space at every airport, they always ran out of overhead bin space so they pressured people to check bags for free or we couldn’t leave on the plane— so I did check my bag to help, and they nearly lost my bag. My bag did not arrive on the luggage belt, another man on my flight and I had to waste our time going to the baggage office to search for our bags. I would only fly southwest again if it was my last choice. Also, my flights were consistently delayed over and over again— at one point they straight up told us we were waiting for the pilot to arrive.

Connecting flight is on time and boarding was a breeze!

Excellent. Would encourage Southwest to keep current boarding procedures with free style seating. Makes for a fantastic experience

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.

Flight left on time and we arrived 25 minutes early! There was a gate available when we arrived so early on a busy Sunday afternoon! Flight attendants came around twice with the drinks cart.

Sitting on the runway after we land for almost two hours! Not sure if we should blame United or Just Dumpy Vance.

Flight was late - I was downgraded from first class to coach

Crew seemed a bit cranky. No seatback screens. But boarding was efficient and on time and we arrived early.

See previous note about the passenger in Denver who threw my husband's bag out of the overhead bin in order to maker room for his own. And the flight attendant back up the new passenger.

Terrible. They wouldn't allow me on my flight on the 14th..

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.

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

There is not one likable thing about this airline. It’s starts with the deceptive pricing and continues through the whole flight. The worst staff I’ve ever experienced way over priced bags absolutely no food or drink (unacceptable and you should be embarrassed) the seats are cramped and uncomfortable there is no entertainment there is nothing about this trash airline that constitutes any amount of money. It’s worse than spirit and way more expensive it is disgraceful. Do not travel with Allegiant I repeat do not bother no matter what they say the price is it is never ever going to be the right choice I’m mind blown at how awful the entire experience was I’m embarrassed that I chose so poorly I cannot reiterate enough how beyond horrible this company and its staff are, not one person on this flight or at the airport is qualified to sweep up trash on a city sidewalk they should certainly never be given any job that requires a brain or manners or communication with human beings, what a disgrace to the human race. Your criminal chiselers and should be put out to pasture

Great flight. Friendly staff. Free snacks and drinks would be nice. I would love fewer taxes and fees added on.

My 90 year old father flew with me. He needed wheel chair assistance and is nearly deaf. The staff was amazing with him.

It was fine. Nobody was outstandingly friendly but no one was rude and everything was smooth . The captain thanked us for flying but no one greeted me as I walked on the plane or as I exited which is the least they could do lol

Clean, friendly, roomy. But check-in from the phone link was terrible. Repeated attempts wouldn’t save at the final step. Just kept spinning! It was very frustrating. Finally, I used the app (vs website link) to check-in which worked very smoothly on the first attempt.

Check in on the web portal was cumbersome! After several attempts I finally got the boarding pass.

Excellent flight and even arrived 23 min early. No entertainment , or wi fi on board, but I downloaded a couple of movies beforehand which kept me entertained. Really like flying Allegiant airlines.

WE were delayed about an hour and never any communications from the employees working the gate. We also were moved to a total of three gates.

I love how they show love to their customers and care about them too.

There was no inflight service. Once we landed we were delayed to find a gate for an hour and a half which was 1/2 the total time in the air.

The chicken wrap was tiny ($13 for what looked like a 1/3 of a normal wrap?) and disgusting.

It was good experience this time. The flight was on time.

There was a delay with the plan which cause the flight to leave later and once arrived in Chicago there was another delay and some passengers missed their connecting flights

The gate agent had a really bad attitude and refused to help me get on the standby list. She just handed me a card and said I needed to call a number. I asked her to help with the AA app on my phone and she just shrugged and said she didnt know. After a few phone calls, I eventually just went to a different gate agent on the other side of the terminal and got the help I needed.

Overall, my last three trips on American Airlines have all been either delayed or "rescheduled" due to mechanical issues. At least on delay caused me to miss two possible connecting flights each later than the first. My last option for my last connection required the assistance of the onsite service desk (O'Hare Airport). The wait time for the service desk was such that it jeopardized getting booked on the last connecting flight available for the night. Suffice it to say, my latest experiences with American Airlines have caused me extensive loss of productive business and personal time and can therefore be classified as significantly less than satisfactory.

Waiting for gate in RDU for more than 20mins is crazy.

American Airlines was great and worked very hard to change my ticket so I could get an earlier, direct flight back to Dallas. However, I was informed that Kayak made mistakes with my itinerary and classified my ticket as desiring to be on the earlier flight instead of taking the necessary step of calling AA to get me on the standby list. This ended up keeping me from being added to the standby list and delayed me getting home by 6 hours. I am happy to discuss this further with Kayak so they can correct their procedures so this won't happen again.

Waited for oxygen tanks for 30 minutes after boarding was complete.

We flew in first class. The crew did not offer drinks before the flight took off, but they treated us well during the flight. The food was excellent. There was actually too much food served, but it was nice to have all the options.

There's no seats that lean back with little leg space i wad uncomfortable the entire flight. Your charges for extra baggage is despicable and costly!!

Remind customers of the need to have passport or new ID for boarding.

Flight was canceled. Most upsetting was message from Kayak, stating that the flight was canceled and click with Kayak for details regarding rebook, refund details. THERE'S NO INFORMATION PROVIDED BY KAYAK EXCEPT THAT FLIGHT IS CANCELED. AND NOW THIS SURVEY TO FIND OUT HOW WAS THE FLIGHT !!!!!!!

The flight never took off and we spent 7 hours at the airport

Gate not determined until I got to the airport - hard to plan the trip to the airport.

There was no food and no entertainment, so I'm not sure why these are even in the survey, as my understanding is frontier does not ever offer food without a few, not even a snack, and there are no screens so unless the flight safety talk is our entertainment why ask how we liked it?. One of the flight attendants say in the back of the plane as people filed in to their seats, yelling orders about where to put baggage and telling people to hurry up. It was the least professional experience I've ever had on a flight.

Good for a budget airline! It was easy to get on, staff was really nice. Can’t say anything about the food or entertainment because it wasn’t available, which is fine.

This company socks. It's fraud. They canceled our flight yesterday, and today we were late because of a really long line at the check in bag. At the rebook station, there was ton of people. The workers were all rude. I am gonna make a report to FTC.

Not clean and was told I would get a great seat and it was not great at all

Delayed. Text notifications were slow. Not much information o what was happening. Boarding was slow and confusing. Wasn’t even offered water other flight. Had to ask. No entertainment at all. Felt like.a Greyhound bus.

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

Information on your arrival and departure airports