$400 Find Cheap Flights from Seoul 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 Seoul to Illinois departing on 12/1. 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

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 Seoul to Illinois.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seoul to Illinois.
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Flight Deals

Book Cheap Seoul 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 Seoul 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 Seoul to Illinois

Fri, Feb 6 - Tue, Feb 10
United Airlines Logo
6:00 pm - 10:12 amICN-MLI
31h 12m2 stops
United Airlines Logo
10:47 am - 5:40 amMLI-ICN
27h 53m2 stops
$591United Airlines
Find Deal
Tue, Dec 23 - Wed, Feb 11
United Airlines Logo
6:00 pm - 11:14 pmICN-ORD
20h 14m1 stop
United Airlines Logo
4:16 pm - 5:40 amORD-ICN
22h 24m1 stop
$591United Airlines
Find Deal
Thu, Dec 25 - Wed, Feb 11
Alaska Airlines Logo
8:35 pm - 6:29 amICN-ORD
24h 54m1 stop
Alaska Airlines Logo
8:00 am - 6:35 pmORD-ICN
19h 35m1 stop
$597Alaska Airlines
Find Deal
Sat, Dec 27 - Tue, Feb 10
Alaska Airlines Logo
8:35 pm - 11:59 pmICN-ORD
18h 24m1 stop
Alaska Airlines Logo
6:06 pm - 6:35 pmORD-ICN
33h 29m1 stop
$598Alaska Airlines
Find Deal
Fri, Feb 6 - Tue, Feb 10
American Airlines Logo
7:15 pm - 3:27 pmICN-MLI
35h 12m1 stop
American Airlines Logo
7:31 am - 4:45 pmMLI-ICN
42h 14m2 stops
$619American Airlines
Find Deal
Tue, Apr 14 - Tue, Apr 21
Delta Logo
7:20 pm - 12:36 amICN-STL
19h 16m2 stops
Delta Logo
6:00 am - 5:20 pmSTL-ICN
21h 20m2 stops
$629Delta
Find Deal
Thu, Feb 12 - Mon, Feb 16
American Airlines Logo
6:50 pm - 1:49 pmICN-STL
33h 59m2 stops
American Airlines Logo
5:14 am - 4:45 pmSTL-ICN
20h 31m1 stop
$689American Airlines
Find Deal
Thu, Feb 12 - Mon, Feb 16
Delta Logo
7:30 pm - 9:04 amICN-STL
28h 34m2 stops
Delta Logo
7:05 pm - 3:30 pmSTL-ICN
29h 25m2 stops
$692Delta
Find Deal
Sat, Apr 11 - Tue, Apr 21
Korean Air Logo
6:40 pm - 11:10 pmICN-STL
18h 30m1 stop
Korean Air Logo
8:50 am - 5:20 pmSTL-ICN
18h 30m1 stop
$744Korean Air
Find Deal
Tue, Nov 18 - Thu, Nov 27
Korean Air Logo
9:35 am - 12:34 pmICN-MDW
17h 59m1 stop
Korean Air Logo
5:34 pm - 5:45 amMDW-ICN
21h 11m1 stop
$1,900Korean Air
Find Deal
Booking Insights

KAYAK's insights & trends for Seoul to Illinois flights

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

What is the cheapest Seoul to Illinois flight route?

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

The cheapest ticket to Illinois from Seoul found in the last 72 hours was to Chicago, at $777 round-trip. The most popular route is from Incheon Intl Airport (ICN) to Chicago O'Hare Intl Airport (ORD), and the cheapest round-trip airline ticket found on this route in the last 72 hours was $777.

Can I save money by flying with a layover from Seoul 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.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 2 stops layover the cheapest option at $754 on average.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Seoul 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 Seoul to Illinois is November, when tickets cost $820 (return) on average. On the other hand, the most expensive months are January and August, when the average cost of round-trip tickets is $1,683 and $1,554 respectively.

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

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

When flying from Seoul to Illinois, you should consider leaving on a Tuesday and avoid Fridays if you are looking for the best rates. For your return to Seoul, you’ll find the best rates on Tuesdays and the most expensive ones on Fridays.

How far in advance should I book a flight from Seoul 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 Seoul 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 Seoul to Illinois, you should book around 5 weeks before departure, which saves you about 12% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 10 weeks before departure.

Good to know

Low seasonFebruary
Cheapest flight$400
Best time to beat the crowds with an average 17% drop in price.
Most popular time to fly and prices are also 23% lower on average.
Flight from Incheon to Chicago Midway Airport

FAQs - booking Illinois flights

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

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Seoul 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 Seoul 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 Seoul 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 Seoul 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 Seoul 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 in the evening, when round-trip flights cost $1,098 on average. Morning departures are around 32% more expensive than evening flights, on average. The most expensive time of day to fly to Illinois is generally at night, which is peak travel time and where the average cost of a ticket is $1,995.

Reviews of the top 5 airlines serving from Seoul to Illinois

 
See real verified KAYAK customer reviews for airlines flying from Seoul 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 Seoul 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.
8.4
Korean AirOverall score based on 1157 reviews
8.3Comfort
8.5Boarding
8.1Food
8.2Entertainment
8.7Crew
Airline reviews

It’s great, long flight and arrive safe at destination

10.0 ExcellentAye, Oct 2025ICN - MSP
Read more Korean Air reviews

It’s great, long flight and arrive safe at destination

Everything was excellent as I expected. They also had a very caring crew. I had a headache and asked a Tylenol. The crew members kept checking with me how I was doing.

They were trying to get people to check luggage because the over head compartments were full but when we boarded there were lots of empty places that people could have put the luggage.

I can't believe they put my wife and I in the two middle seats! It is a very long flight and we had single flyers on either side of us blocking the way to the bathroom! There's no reason to not give one of us the isle seat so we could have managed bathroom needs and snacks with convenience. So I think very poorly of Korean air to put us both in the middle, I've never had that happen before and will probably avoid this airline in the future because of this. We tried to have them change it but they didn't so you pretty much lost a customer because of it.

There could have been better spacing of the passengers, it was crowded in some parts of the plane then other while rows were empty

Plane took off on time and I had the whole row to myself!

One of the flight attendants stepped on my foot. I was on the aisle seat. A lady inside needed to get out. So Instood. Just then, a flight attentendant came wuicklybtheoughbthe aisle and stepprd on my sock covered toes. I let out a small sound. She stopped momentarily, but didn’t ask how I was just took off of the aisle. Never came back to see how I was. Fortunately, I was not really hurt other than a slight soreness in my toes. But I found that to be very negligent.

This flight was a superior flight in all regards. Extremely pleasant experience.

Korean Air is unlike any other major airline I have flown with. The grace and respect that the staff has from check in to de-boarding is unmatched. The flight attendants this time were especially wonderful to my five little children. They helped us rearrange to more suitable seating, brought our children’s meals, and patiently waited for them in the aisles when they had to use the bathroom. We felt so welcome and comfortable. I really appreciate the meal voucher when our flight was delayed. I am grateful to have had such an stress-free experience.

It's good overall. Flight was packed. Inflight entertainment choices were lacking.

Better screens, it would have been nice to have more comfortable seats.

2nd major delay due to maintenance issues. 1st delay missed my connecting flight.

It was great, but my bag was not loaded onto the connecting flight. I'm currently getting it resolved. If this isn't a problem, everything else was excellent.

Very clean ,flight attendants very professional,nice , Boarding was very easy

The aircraft was massive (A-380) and became crowded with 400+ passengers on board.

The plane hasnt left im stuck in seatle still my flight has been grounded for almost 5 hours

Love flying Asiana. Been using it for over a decade now.

Coming back to America was a peaceful flight everyone and everything was perfect

The staff was courteous and the flight was very smooth. It was so nice to see the captain greeting the passengers at the end of the flights.

Flight was too cold. I wore a regular cotton tee and it wasn’t enough. It was a night time flight so I would have thought a blanket would be provided to passengers. A 4 hour flight and no options for a meal? I flew Asiana the next day from Seoul to Manilla. Same duration, 4 hours. They give everyone a pillow and blanket and serve a meal. Why is United so cheap and holding back meals and amenities? Also, they promote too much gay stuff and DEI in their advertisements. Please be mindful of other beliefs and don’t shove your gay ideology down my throat.

I truly love flying with Delta. They have always treated me with the upmost respect

Our flight attendant in FIRST CLASS was one of the worst I’ve ever had. She was not at all pleasant, nor particularly good at her service.

Everything went well and was good. Nothing exceptional, but no complaints either. Cheap seats are pretty comfortable.

DELTA does a terrific job making sure you are well taken care of during the flight, gives you assurance before the flight through numerous email notifications about your upcoming flight & lastly good follow up after the flight making sure your needs were mat. It has been, is & will continue to be my carrier of choice in all my future travels. Good Job DELTA

Staff were friendly and happy. Delta could make sure passengers that don't have the app know of changes. Without Kayak I would not have known about the change of gate or the delay. Kayak was faster to notify me.

They ended up paying for the bag twice, but the counter wouldn't take my baggage receipt. Left it to me to resolve. Not sure how to resolve the issue.

The customer service before board was very rude and when I expressed my concerns about making the connecting flight she laughed and told me I bought the wrong ticket. I explained once it showed the flight was delayed it no longer let me change seats or anything. I was trying to upgrade to make sure I would get to the next gate on time.

Non stop on long haul is the way to go. Great experience

Seats comfortable, service and food very mediocre, staff not very attentive, worse than many other our flights with Delta.

Overall good experience; however, there was one flight attendant who was rather rough compared to everyone else. Everything else was good: entertainment, food. Delta keeps on delivering! Thank you!

Flight was delayed only slightly before takeoff due to traffic control. However, the flight arrived early to ORD. Good flight. United has been very reliable for me.

Another delayed flight. When the delays exceed the duration of the flight, it’s a problem.

After boarding the plane in Chicago, the passengers were told that there was a technical problem with the plane. Passengers remained on the plane as they tried to fix the problem. After what was probably an hour passengers were told that there was a need to change planes as the problem was not solved. Passengers disembarked and boarded another plane. After taxing to the runway and waiting for takeoff, passengers were told that owing to the thunderstorm the flight was unable to take off but would try and reroute. After some time passengers were told there wasn't enough fuel for the new route and the plane had to return to the gate for additional fuel. after another log delay the flight got underway. On the plane there was food, drinks, ice or entertainment. We were a glass of water, which appeared rationed. Flight arrived about 5 hours late. The pilot was fantastic and communicated with the passengers throughout the ordeal.

Excellent all round, first time flying United. App is very helpful.

Efficient all round, very good crew. Short flight so the food, of course, was just snacks

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.

Trip was great. A wild landing in Ottawa with the wind and rain, but the pilot did a great job. Always love flying United.👍

Excellent experience. Starting with the agent at the Premier bag drop who noticed I was very early for my scheduled flight and offered to rebook me on an earlier flight with my seat preference. She would not let me leave the counter until she knew that all of the changes and new boarding pass showed up on my United app. At the gate, the flight boarded quickly such that we departed early and the flight was smooth. We arrived 20 minutes early at ORD and I was able to be home in time for dinner. One of the best flights I've had.

Salina to travers city was great! But the sept 24 Tranverse city was not! Traverse city to chichago was cancelled, i went to Denver & got to Salina 6 hours later!

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.

Air Canada cancelled our flight and reschedule it 26 hours later that completely interrupted my family's long waited Japan trip, it wasn't due to natural reason such as weather but under the company's control. On the day we wasted 9 hours of our time from 6am to 3pm, including a few hours in the customer counter waiting for supervisor to handle our rescheduling. When we came to the counter for rebooking help there were at least 4 employees on the counter but we were told they were not trained to handle customer rebooking, we were also told the supervisor could come 10:30 to handle our rebooking, but she showed up more than one hour later, the end result was exactly the same so the few hours we spent waiting for her was completely wasted; We already prepaid hotel and all the tickets for the our stay in Tokyo so all of the cost for the first day is completed wasted; The $80 meal voucher issues was far less than our financial loss due to the financial cancellation, and it was not surprisingly invalid (as Your company screw up everything possible along the flight), the vouchers were supposed to last 72 hours, when we tried to used it at our lounge next day less than 24 hours from its issuing at a designated restaurant, the worker there couldn't scan the vouchers after multiple tries on all 4 vouchers issued, so we had to pay the food from our own money; For the two return flights they were also full of unfortunate events that caused bad experience and further delay and waste of our time, both flights departed late and the last leg had another significant delay of more than half an hour after touchdown, the gate was for some reason not available so we waited more than half an hour, when we got out of plane it was almost one hour later than the supposed arrival time; The gate you arranged is the farthest in Vancouver airport, also was the luggage pickup location in Seattle airport; We also called customer service for rescheduling help and after a long time wait (more than an hour) we got a call back but the CS representative was equally clueless and unhelpful. Other than a fatal crash, your company couldn't do anything right and provided the worst service possible among the tons of flights we have taken in our lives.

The free Wi-fi for Aeroplan members was a great touch. The time passed quickly. I found the seats seemed a little closer together than I remember. Not Air Canada's fault, but we were about 20 minutes late landing because the airport was too busy. We had to circle around for a while. The boarding and disembarking went very smoothly.

Bad service as well. Another 3hr delayed flight from chicago to Charlotte.

Very bad service the way back we was on the way for r two days very bad condition and waiting for luggage till now

United had no (zero) record of our flight. It took over an hour of us standing in line with surly employee while others waited to get resolved. I have never experienced such poor service and poor empathy.

Or the greatest and it ended up picking us up from Chicago to Toronto not sure who was tesponsible for the 4 hr delay. United should have been properly prepared for a scheduled flight from Austin to Chicago and they were not.

The service was good ... I wondered if the stewardess was OK though as she seemed quite sad.

Terrible food, unprofessional flight attendants, and an uncomfortable seat. The food they provided was the worst I have ever had since I flew. They were worse than any cheap food you can get at convenience stores. A flight attendant talked to me in an insulting and demanding manner. If she wanted to say something, she should have said it professionally and kindly. No flight attendants served any drinks or snacks. If I needed a drink or snacks, I had to get up from my seat and go to the airplane's back area and serve myself. What were the flight attendants doing during their work shifts? A man sitting in front of me fully extended his chair to the back, so I had virtually no space to eat with reasonable comfort. Many people were so inconsiderate of others and fully extended their chairs to the back that they did not have enough space to eat. Flight attendants ignored these situations and never bothered to tell passengers to return their chairs to upright positions during the mealtime. I want to be comfortable and don't care if others feel uncomfortable because of me. Those were the dominant thoughts of people in that airplane. I paid more than $2000.00 for this terrible experience.

My flight was overbooked and they would not let me board. I had to book another flight and pay the full amount of that flight. I did not get any help at all from Air Canada or United Airlines.

Very nice. Cabin crew is very attentive and professional. So nice!

Everything you need to know for your flight from Seoul 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.

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