$63 Find Cheap Flights from Washington, D.C. to Illinois - Compare and Save

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Washington, D.C. to Illinois departing on 9/30. 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.
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Cheap Flights from Washington, D.C. to Illinois

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Chicago
Chicagononstop$238
Moline
Moline1 stop$285
Peoria
Peoria1 stop$283
St. Louis
St. Louis1 stop$123
Decatur
Decatur1 stop$304
Chicago
Chicagononstop$238
Moline
Moline1 stop$285
Peoria
Peoria1 stop$283
St. Louis
St. Louis1 stop$123
Decatur
Decatur1 stop$304

Book Cheap Washington, D.C. 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 Washington, D.C. 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 Washington, D.C. to Illinois

Sat, Aug 1 - Tue, Aug 4
Frontier Logo
9:37 pm - 5:37 pm
BWI
-
STL
21h 00m
1 stop
Frontier Logo
6:34 pm - 7:26 am
STL
-
BWI
11h 52m
1 stop
$123Frontier
Wed, Jul 22 - Tue, Aug 4
Frontier Logo
9:37 pm - 5:37 pm
BWI
-
STL
21h 00m
1 stop
Frontier Logo
6:34 pm - 7:26 am
STL
-
BWI
11h 52m
1 stop
$132Frontier
Tue, Aug 4 - Thu, Aug 6
Southwest Logo
5:15 pm - 6:10 pm
BWI
-
MDW
1h 55mnonstop
Southwest Logo
10:30 am - 1:15 pm
MDW
-
BWI
1h 45mnonstop
$238Southwest
Thu, Sep 3 - Sat, Sep 5
American Airlines Logo
7:03 am - 8:30 am
BWI
-
ORD
2h 27mnonstop
American Airlines Logo
9:05 am - 12:11 pm
ORD
-
BWI
2h 06mnonstop
$243American Airlines
Tue, Aug 4 - Fri, Aug 7
Southwest Logo
7:30 pm - 8:30 pm
BWI
-
MDW
2h 00mnonstop
Southwest Logo
9:00 am - 11:55 am
MDW
-
BWI
1h 55mnonstop
$243Southwest
Mon, Aug 17 - Thu, Aug 20
United Airlines Logo
10:27 pm - 11:40 pm
IAD
-
ORD
2h 13mnonstop
United Airlines Logo
9:39 pm - 12:44 am
ORD
-
IAD
2h 05mnonstop
$245United Airlines
Sat, Aug 1 - Mon, Aug 3
American Airlines Logo
8:06 pm - 9:42 pm
DCA
-
ORD
2h 36mnonstop
American Airlines Logo
5:07 am - 10:50 am
ORD
-
DCA
4h 43m
1 stop
$247American Airlines
Sat, Jul 25 - Thu, Aug 6
Delta Logo
5:18 pm - 8:31 pm
IAD
-
ORD
4h 13m
1 stop
Delta Logo
5:20 pm - 11:26 pm
ORD
-
IAD
5h 06m
1 stop
$257Delta
Thu, Aug 27 - Sat, Aug 29
Delta Logo
5:47 pm - 10:36 pm
IAD
-
MDW
5h 49m
1 stop
Delta Logo
6:42 pm - 11:26 pm
MDW
-
IAD
3h 44m
1 stop
$257Delta
Sat, Aug 15 - Tue, Aug 18
United Airlines Logo
5:45 pm - 7:11 pm
IAD
-
STL
2h 26mnonstop
United Airlines Logo
8:40 am - 11:54 am
STL
-
IAD
2h 14mnonstop
$275United Airlines
Booking Insights

KAYAK's insights & trends for Washington, D.C. to Illinois flights

Get data-powered insights and trends into flights from Washington, D.C. 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 Washington, D.C. 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 Washington, D.C. to Illinois departing in September.

What is the cheapest Washington, D.C. to Illinois flight route?

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

The cheapest ticket to Illinois from Washington, D.C. found in the last 5 days was to Chicago, at $211 round-trip. The most popular route is from Washington, D.C. Reagan-National Airport (DCA) to Chicago O'Hare Intl Airport (ORD), and the cheapest round-trip airline ticket found on this route in the last 5 days was $240.

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

The average price for all round-trip flights from Washington, D.C. 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 $429 on average. Morning departures are around 6% cheaper than evening flights, on average. The most expensive time of day to fly to Illinois is generally in the evening, which is peak travel time and where the average cost of a ticket is $496.

Can I save money by flying with a layover from Washington, D.C. 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 $369, prices are generally cheapest when you fly direct.

What is the cheapest month to fly from Washington, D.C. to Illinois?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Washington, D.C. 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 Washington, D.C. to Illinois is September, when tickets cost $225 (return) on average. On the other hand, the most expensive months are June and May, when the average cost of round-trip tickets is $416 and $398 respectively.

What’s the cheapest day of the week to fly from Washington, D.C. to Illinois?

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

If your flying dates are flexible, you should consider flying to Illinois on a Thursday, as we generally find the cheapest rates on that day for this route. On the other hand, Monday is the most expensive day to fly from Washington, D.C. to Illinois. For your return ticket, we recommend flying on a Friday and avoiding Sundays for the best deals.

How far in advance should I book a flight from Washington, D.C. 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 Washington, D.C. 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 Washington, D.C. to Illinois, you should book around 4 weeks before departure, which saves you about 53% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 17 weeks before departure.

Good to know

Low seasonFebruary
Cheapest flight$63
Best time to beat the crowds with an average 1% drop in price.
Most popular time to fly and prices are also 12% lower on average.
Flight from Baltimore to St. Louis

FAQs - booking Illinois flights

  • How does KAYAK find such low prices on flights from Washington, D.C. 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 Washington, D.C. to Illinois.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Washington, D.C. to Illinois?

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

Reviews of the top 5 airlines serving from Washington, D.C. to Illinois

 
See real verified KAYAK customer reviews for airlines flying from Washington, D.C. 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 Washington, D.C. 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 4251 reviews
8.0Comfort
8.6Crew
8.1Boarding
7.0Food
7.5Entertainment
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.

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.

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

Haven’t flown on SW in years. Flight was on time departing and arriving. Served vegan butter onion flavored pretzels which were bad. Coke served was in a tiny paper cup. Crew was not engaging. Felt like they were going through the motions. Old plane, tight seats and no leg room.

No delays and arrived to destination 30 min early. Staff was super friendly.

Pretty standard flight. We left late, but arrived early. The wifi entertainment is always nice. The free snacks and beverages are simple, but appreciated. I'm tall and the seats are an issue. I can deal with a short flight, but any longer, I have to find another airline where I know beforehand I have extra legroom.

Awesome experience. No in-flight video or meal. Still do not like the boarding process.

On time, good crew, easy flight. Just like the old days!

It was as good as it could be. Flying is not a pleasant experience these days.

The gentleman at the gate I think his name is RIE was exceptional

There was an unruly family behind us that made the short flight miserable!!! The cabin crew did nothing to contain it.

This flight was no comparison to our prior flight. I'm thinking it all has to do with the age of the aircraft.

2 of the seats in row 31 the entertainment system was not working, and one seat the tray table did not go all the way down. Flight arrived early and departed on time which was great.

Waited at the usual crowded gate at DCA where one ends up standing up because there aren't enough seats.

Delayed take-off. Very small plane so very scary with lots of bumps during the flight. Would never fly Delta on short flights in small 80 seaters plane again! Felt relieved when landed.

Inexpensive, got an exit row aisle aeat with no middle passenger, bought a great breakfast sandwich, flight comfortable & arrived ahead of schedule.

I wouldn't say I liked being forced to check my small roller bag at the gate; too many people had bags and were in a higher boarding group.

715PM departure was 2.5 hours late. Received hotel & food voucher but after we already booked a room. Entire team just seemed like they were 2-3 steps behind in execution, and notifcations.

Like: departed and arrived on time. Unlike: Food options for purchase allways bad, 1 of 2 of the crew members not very friendly at all. Seats and leg room aweful. At this point I am thinking on switching to AA.

Over 5 hour delay with minimal updates or ability to standby for alternative flights. During boarding and 1 hr+ wait for takeoff, seats were drenched w water from air conditioning condensation and always leftover crumbs on carpet and seats

After arriving in Chicago, we were taxiing for 1.5 hours with infrequent and untruthful updates about the amount of time it would take to arrive at the gate. Minimally, the team could have provided timing expectations that were more truthful, especially one their original expectations were not met.

United didn’t even try to hold the flight for me. They knew I had a tight connection and when I arrived at the gate less than 10 mins after final boarding the flight had already gone. The gate agent wasn’t even notified that I was on my way. She was told I wasn’t at the airport

Good quick flight on a small but comfortable plane. I'm 6'3 and had plenty of space.

The flight was delayed so we were dead tired, and after that the turbulence was horrible. I was very scared.

Wonderful. Quick boarding. Early departure and we arrived 30 minutes early at our destination. Unfortunately, when you arrive early, there is still a departing aircraft at our gate. We had to park for 30 minutes until the gate was clear. So our early arrival was not really early at the gate. Otherwise it was a quick and smooth flight. Appreciated the efficiency.

Better WiFi. I cannot understand that in 2025, United is so behind on a technology that is now a necessity and still painfully unreliable, slow and keeps disconnecting.

Being stick waiting for gate at ORD cause me to almost miss my connecting flight…being deaf United made no no effort to keep me updated as I couldn’t hear the PA

Almost 2 hour delay in boarding with all standing ready to board at original time. No explanation given.

The seats were extremely cramped, with very little legroom or personal space. There was no room left in the overhead bins for a backpack, and the space under the seat in front was so limited that I could barely fit my bag underneath. Overall, the seating arrangement felt very uncomfortable and overcrowded.

As always, most AA flights that we fly are almost ALWAYS delayed and that too multiple times. Very frustrating

The small flights with Valet Luggage has a poor service

Overall a good experience, however Wifi was not working on the flight.

THe flight was an hour late. You got us on the plan and we sat on the ground for 45 minutes with no information from the pilot whatsoever. Worst flight this year.

Delays with no explanation. It could have been handled better.

Everything was great. Boarding, early departure, early arrival, and deplaning were smooth. Smooth flight.

The flight was scheduled to depart DCA at 12:30 pm but was delayed twice on the ground so that we were finally scheduled to depart at around 4:00 pm. Once we boarded, it was announced that takeoff would be delayed again to fix a hydraulic problem which delayed our eventual takeoff until around 5:00 pm. Once we departed, it was a smooth flight back to ORD. We did not get any explanation about what caused the original significant delay. In my experience, this happens frequently with AA.

Our second leg to Jackson WY was unable to land due to weather. We were flown back to Dallas after stopping in SLC. We were given hotel rooms and vouchers. We were told that we would be back on the same plane in the morning. Instead we were given a different flight with different seats. Not a good experience. No one knew what was going on.

Perfect flight. On time departure and early arrival. Smooth flight.

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

More inflight connection. And leg space is horrible. And the paying for baggage I'd ridiculous!!!

Frontier Airlines was AWFUL. I was an hour early for my flight and the lady refused to check me in. I had to purchase a whole new ticket with a different airline.

I missed a flight because of a delay. I had to buy a new ticket through Southwest.

Bag should not be so much money. This is how Frontier takes advantage of customers

Frontier is definitely a good option for people traveling light or on a budget - just remember to bring your own entertainment and your own headphones if you need them.

Never offer anything to drink ☹️ Flight delayed gate moved poor communication

It’s a cheap airline. I wish they had better seats.

Seats are cramped and very uncomfortable. You have to pay for everything and it is too expensive.

Everything you need to know for your flight from Washington, D.C. to Illinois

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.