$363 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 12/15. 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, May 1 - Thu, May 7
Alaska Airlines Logo
8:35 pm - 11:58 pmICN-ORD
17h 23m1 stop
Alaska Airlines Logo
7:00 am - 6:35 pmORD-ICN
21h 35m1 stop
$456Alaska Airlines
Find Deal
Mon, Dec 15 - Wed, Dec 24
American Airlines Logo
7:15 pm - 7:14 amICN-ORD
26h 59m2 stops
American Airlines Logo
4:05 pm - 4:45 pmORD-ICN
33h 40m2 stops
$567American Airlines
Find Deal
Thu, Jan 29 - Sat, Jan 31
Hawaiian Airlines Logo
8:35 pm - 2:38 pmICN-ORD
33h 03m1 stop
Hawaiian Airlines Logo
8:00 am - 6:35 pmORD-ICN
19h 35m1 stop
$571Hawaiian Airlines
Find Deal
Thu, Jan 29 - Sat, Jan 31
Hawaiian Airlines Logo
8:35 pm - 2:38 pmICN-ORD
33h 03m1 stop
Hawaiian Airlines Logo
8:00 am - 6:35 pmORD-ICN
19h 35m1 stop
$576Hawaiian Airlines
Find Deal
Tue, Apr 14 - Tue, Apr 21
United Airlines Logo
11:30 am - 6:22 pmICN-STL
20h 52m1 stop
United Airlines Logo
7:06 pm - 4:20 amSTL-ICN
19h 14m1 stop
$651United Airlines
Find Deal
Tue, Apr 14 - Tue, Apr 21
United Airlines Logo
11:30 am - 6:22 pmICN-STL
20h 52m1 stop
United Airlines Logo
11:25 am - 4:20 amSTL-ICN
26h 55m2 stops
$656United Airlines
Find Deal
Thu, Feb 26 - Sat, Feb 28
Delta Logo
2:30 pm - 9:56 amICN-MDW
34h 26m2 stops
Delta Logo
5:00 pm - 3:30 pmMDW-ICN
31h 30m1 stop
$1,160Delta
Find Deal
Mon, Dec 15 - Sat, Dec 27
Delta Logo
9:45 am - 11:55 amICN-MDW
17h 10m1 stop
Delta Logo
5:59 pm - 3:30 pmMDW-ICN
30h 31m1 stop
$1,173Delta
Find Deal
Tue, Mar 3 - Sun, Mar 8
Korean Air Logo
9:35 am - 12:46 pmICN-MDW
18h 11m1 stop
Korean Air Logo
9:32 am - 4:50 pmMDW-ICN
17h 18m1 stop
$1,311Korean Air
Find Deal
Mon, Mar 9 - Fri, Mar 27
Korean Air Logo
9:45 am - 4:26 pmICN-MLI
20h 41m1 stop
Korean Air Logo
5:50 am - 3:50 pmMLI-ICN
20h 00m1 stop
$2,839Korean 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 $1,317 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 $1,317.

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 $854 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 September, when tickets cost $742 (return) on average. On the other hand, the most expensive months are January and August, when the average cost of round-trip tickets is $1,979 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 Friday and avoid Wednesdays 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 3 weeks before departure, which saves you about 17% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 10 weeks before departure.

Good to know

Low seasonMarch
Cheapest flight$363
Best time to beat the crowds with an average 9% drop in price.
Most popular time to fly and prices are also 8% lower on average.
Flight from Seoul Incheon Airport to St. Louis

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 1177 reviews
8.2Entertainment
8.5Boarding
8.1Food
8.7Crew
8.3Comfort
Airline reviews

Great service and comfort level. You can have more of vegetarian food options.

10.0 ExcellentAnonymous, Nov 2025ICN - SFO
Read more Korean Air reviews

Great service and comfort level. You can have more of vegetarian food options.

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.

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.

The customer service was excellent. They noticed that our connecting flight was scheduled too closely for us to complete customs, so they changed the flight. Our initial flight was delayed, and they were able to get us on another flight, all without charging us any additional fees. I would fly them again anytime!

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.

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 fly Delta all the time, have Platinum Medallion status. But this route seems to have major problems with delays and seems to never leave on time! Have only taken it twice in the last two weeks, and each time it had delays of more than 1 hour... very disappointed!!!!

Good seats in Main cabin, excellent service and excellent landing

My flight was cancelled with no explanation after I had already cleared security. I was given 4 options to rebook, only one being non-stop like I had paid for. I grabbed it. It was 4 plus hours later and then took off even later. Biggest complaint is that I booked early and had an aisle seat. They gave me a "window" seat in front of the exit row, so the seat did not decline. I weigh all of 103 #s and it was tight for me! For what I paid, I feel I was kind of ripped off. I think they should have given me the empty comfort seat for the inconvenience. There was no apology nor any explanation as to why the flight was cancelled. My guess is it benefitted Delta in some way.

Very smooth, on-time, and pleasantly uneventful flight. The team at the gate and on board were professional and genuinely courteous. The pilot kept us well updated throughout, and both takeoff and landing were steady and enjoyable without any drama. Just a good, solid flight. Thank you! 💗

Staff was exceptional! Everyone was kind, professional and friendly making the trip very pleasant. Thank you!

No lunch on a x-country flight scheduled for 10:50 am departure, arrived 5+ hrs later. That requires a black box label before you pay for the tickets. Worst, when I checked in online, it's specifically said that lunch was served on his flight for economy Plus passengers.

We had a lot of really rough weather but that was not Delta's fault. Pilot was amazing.

One of the best airlines that I flew on, the flight attendants were very attentive and professional.

First, Delta needs more flights to/from Miami. Second, a 1000pm leaving at 1230pm is unacceptable from their biggest airport world hub. Another aircraft could have been used such as the aircraft scheduled to be used in the morning for that exact same route. Yes, I did get me there but the lack of sleep the next day didn't help me enjoy my entire trip since I was busy with activities during the weekend. This can be and is expected from Spirit (going bankrupt) and Frontier (despite they're nickel and dimers). But from Delta's World Hub? That's totally unacceptable!

This flight was straightforward and without difficulty. Service was OK, but I continue to be underwhelmed by level of attention given to Sky Priority passengers.

Very bad! They kept delaying my flight and wouldn’t do anything about it

Door to door, the crew and staff were amazing. It was a stressful travel day with delays, but they were focused on customers and doing what they could to get us to our destinations.

United has come a long way, it’s been a fantastic experience traveling with them.

This flight leg was fantastic - super comfortable and a great selection of things to watch on the TV. Staff were excellent, really above and beyond.

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.

It's kindof ridiculous that your system is even asking me about this since my flight was canceled and I wasn't rescheduled.

3 hr delay at the gate while they were doing maintenance. Next time, do not board passengers while maintenance is being performed

Digital check in is very poor with air canada compaired to other airlines

Baggage delayed we had to catch our cruise without any clothes 😒

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.

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.