$62 Find Cheap Flights from Seattle 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 Seattle to Illinois departing on 2/6. 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 Seattle to Illinois.
These are the airlines KAYAK users have selected most often from within our search results in flight searches from Seattle to Illinois.
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Cheap Flights from Seattle to Illinois

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Chicago
Chicagononstop$176
Moline
Moline1 stop$289
Peoria
Peoria1 stop$270
Bloomington
Bloomington1 stop$299
Champaign
Champaign1 stop$268
Springfield
Springfield1 stop$249
St. Louis
St. Louis2 stops$242
Decatur
Decatur1 stop$309
Paducah
Paducah2 stops$644
Chicago
Chicagononstop$176
Moline
Moline1 stop$289
Peoria
Peoria1 stop$270
Bloomington
Bloomington1 stop$299
Champaign
Champaign1 stop$268
Springfield
Springfield1 stop$249
St. Louis
St. Louis2 stops$242
Decatur
Decatur1 stop$309
Paducah
Paducah2 stops$644

Book Cheap Seattle 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 Seattle 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 Seattle to Illinois

Thu, Jan 8 - Thu, Jan 15
Alaska Airlines Logo
8:30 am - 2:38 pm
SEA
-
ORD
4h 08mnonstop
Alaska Airlines Logo
6:06 pm - 8:56 pm
ORD
-
SEA
4h 50mnonstop
$176Alaska Airlines
Fri, Jan 9 - Sat, Jan 10
Alaska Airlines Logo
5:50 pm - 11:50 pm
SEA
-
ORD
4h 00mnonstop
Alaska Airlines Logo
8:00 am - 10:46 am
ORD
-
SEA
4h 46mnonstop
$177Alaska Airlines
Mon, Jan 5 - Fri, Jan 9
Hawaiian Airlines Logo
5:49 pm - 11:59 pm
SEA
-
ORD
4h 10mnonstop
Hawaiian Airlines Logo
8:00 am - 10:46 am
ORD
-
SEA
4h 46mnonstop
$178Hawaiian Airlines
Sun, Jan 11 - Wed, Jan 14
American Airlines Logo
2:04 pm - 8:15 pm
SEA
-
ORD
4h 11mnonstop
American Airlines Logo
10:27 am - 1:08 pm
ORD
-
SEA
4h 41mnonstop
$179American Airlines
Fri, Jan 9 - Sun, Jan 11
United Airlines Logo
12:57 pm - 12:28 am
SEA
-
ORD
9h 31m1 stop
United Airlines Logo
7:54 pm - 10:43 pm
ORD
-
SEA
4h 49mnonstop
$183United Airlines
Fri, Jan 30 - Mon, Feb 2
United Airlines Logo
9:00 am - 8:58 pm
SEA
-
STL
9h 58m2 stops
United Airlines Logo
4:35 pm - 10:59 pm
STL
-
SEA
8h 24m1 stop
$242United Airlines
Thu, Jan 1 - Tue, Jan 6
American Airlines Logo
12:14 am - 8:35 am
SEA
-
STL
6h 21m1 stop
American Airlines Logo
9:25 am - 3:34 pm
STL
-
SEA
8h 09m1 stop
$263American Airlines
Mon, Jan 5 - Mon, Jan 12
Hawaiian Airlines Logo
6:05 pm - 11:59 pm
SEA
-
STL
3h 54mnonstop
Hawaiian Airlines Logo
2:50 pm - 5:25 pm
STL
-
SEA
4h 35mnonstop
$265Hawaiian Airlines
Sat, Mar 7 - Mon, Mar 9
Delta Logo
11:05 pm - 10:19 am
SEA
-
BMI
9h 14m1 stop
Delta Logo
3:59 pm - 9:54 pm
BMI
-
SEA
7h 55m1 stop
$393Delta
Tue, Mar 3 - Mon, Mar 9
Delta Logo
5:59 pm - 2:54 pm
SEA
-
BMI
18h 55m2 stops
Delta Logo
3:59 pm - 9:54 pm
BMI
-
SEA
7h 55m1 stop
$407Delta
Booking Insights

KAYAK's insights & trends for Seattle to Illinois flights

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

What is the cheapest Seattle to Illinois flight route?

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

The cheapest ticket to Illinois from Seattle found in the last 72 hours was to Chicago, at $186 round-trip. The most popular route is from Seattle (SEA) to Chicago O'Hare Intl Airport (ORD), and the cheapest round-trip airline ticket found on this route in the last 72 hours was $186.

Can I save money by flying with a layover from Seattle 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 $315, prices are generally cheapest when you fly direct.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Seattle 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 Seattle to Illinois is January, when tickets cost $228 (return) on average. On the other hand, the most expensive months are December and June, when the average cost of round-trip tickets is $381 and $329 respectively.

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

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

For Seattle to Illinois, Wednesday is the cheapest day to fly on average and Sunday is the most expensive. Flying from Illinois back to Seattle, the best deals are generally found on Wednesday, with Sunday being the most expensive.

How far in advance should I book a flight from Seattle 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 Seattle 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 Seattle to Illinois, you should book around 3 weeks before departure, which saves you about 46% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 21 weeks before departure.

Good to know

Low seasonJanuary
Cheapest flight$62
Best time to beat the crowds with an average 20% drop in price.
Most popular time to fly with an average 9% increase in price.
Flight from Seattle to St. Louis

FAQs - booking Illinois flights

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

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight from Seattle 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 Seattle 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 Seattle 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 Seattle 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 Seattle 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 $294 on average. Morning departures are around 53% more expensive than evening flights, on average. The most expensive time of day to fly to Illinois is generally in the morning, which is peak travel time and where the average cost of a ticket is $450.

Top tips for finding cheap flights to Illinois

  • Looking for a cheap flight? 25% of our users found tickets from Seattle to the following destinations at these prices or less: Chicago $174 one-way - $324 round-trip

Reviews of the top 5 airlines serving from Seattle to Illinois

 
See real verified KAYAK customer reviews for airlines flying from Seattle 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 Seattle 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
Alaska AirlinesOverall score based on 11427 reviews
8.1Boarding
8.5Crew
7.1Food
7.8Comfort
7.0Entertainment
Airline reviews

Late boarding, older plane. Great flight, no issues. Very cold inside the plane.

10.0 ExcellentTerri, Dec 2025
SEA - MSP
Read more Alaska Airlines reviews

Late boarding, older plane. Great flight, no issues. Very cold inside the plane.

The plane was old so the seats were very worn out. The seats were hard, uncomfortable, and caused me actual pain. The lights were too bright. The flight itself was fine.

1. Denial of Basic Needs (SEA): Upon arrival in Seattle, the wheelchair attendant refused my urgent request to use the restroom, insisting on scanning documents first. She eventually took me to a restroom but then abandoned me and my autistic son at an unstaffed, deserted gate for over four hours. When I called the accommodation line for help, I was told to "get someone's attention," which was impossible. My son, traumatized by the prospect of me yelling for help, was forced to wander the terminal to find assistance. 2. Revocation of Accommodations & Threats: At the gate, an agent stated I had no accommodations on file, despite my previous leg having them. When I showed the app (where my bulkhead seat was erased and replaced with Row 14), he denied the evidence. When I attempted to advocate for my immobilized leg, he threatened to "yank me from the flight" if I said one more word. He coerced me into agreeing that I was "asking for accommodations for the first time" before he would allow assistance, effectively forcing me to falsify the situation under duress. I complied only out of fear of being stranded in a strange city. 3. On-Board Negligence and Injury: Because my bulkhead seat was revoked, I was forced into Row 14. With my leg immobilized and unable to bend, it extended into the aisle. During boarding and the flight: 16 different passengers tripped over my injured leg. 6 rolled luggage bags were pulled over my injured leg. The Flight Attendant (FA) was one of the people who tripped and drove luggage over me. I reported the issue to the FA after 10 trips and 3 luggage impacts. He ignored me. He only addressed me later to ask me to move my immobilized leg for beverage service. I informed him again: "16 people have tripped, 6 luggage runovers, I cannot bend it." He provided no medical aid and no incident report. 4. Resolution and Trauma: Eventually, a different employee noticed my distress and my original paper boarding pass showing the correct bulkhead assignment. He asked me to move up. I broke down in tears, terrified that moving would cause the gate agent to remove me from the plane as threatened. We were eventually moved to the bulkhead, but the damage was done. My autistic son was traumatized by watching his mother be trampled and threatened. 5. Post-Flight: I called to report these injuries, but was disconnected after a 45-minute hold. I require a formal record of this injury and these violations.

Larger seats with a bit more room would be good! Thanks for all your hard work. I think we are all feeling a bit down these days economically and your positive attitudes, both from SJC to Seattle and from Seattle to Bozeman makes more of a difference than you can see! Thank you and Merry Christmas! I hope all your financial needs are met and that very good things come your way.

We flew economy, it was what I expected. The seats are too upright for me

I purchased a 1st class ticket and unfortunately the main flight attendant was not the best and seemed more interested in her phone than the passengers at times. Then the plane didn’t get restocked and the only snacks for this flight were pretzels. However I would like to say that the rest of the flight crew and ground crew at the airport we’re great, especially the people that wheeled me around the airport some and then the one getting me to the plane and the automated wheelchair that wheeled me through the airport.

Typical domestic flight. No entertainment. You have to use your own devices and provided entertainment didn’t work. Pretzels and water of flight over 4 hours is unacceptable. Meals should be provided on long flights. But it’s about the money and not customer service. You should just issue the bag of pretzels at the gate and water bottle in seat and just do away with flight attendants because they do nothing on domestic flights

Very good. Easy check in, attentive flight attendant, and on time departure/landing.

Again Alaskan and Hawaiian need to consolidate check-in, allow seat reservations on both flights. I wound up in last row because I couldn’t reserve better seat.

I would like if it had happened already. I'm still waiting for it.

Lady Pilot was perfect in every way wheels up to wheels down communication, professionalism, excellent on time departure and on time arrival, excellent communication! Fantastic job with Superb attitude!!

The food is terrible. The staff is wonderful. Comfort is good.

Left on time, a bit delayed due to headwinds most of the trip.

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.

Unfortunately, I was put into the middle seat in the first row of premium seating. Sounds nice right? No! that is the worst seat in the plane. I wish I was in economy rather than be in that seat! There is no seat back pocket, no tray table, no charger. Nothing! so unless you're row mates are willing to let you share their basic amenities any flyer should have, you are stuck. It was the worst experience ever! And the flight attendant forgot to take my drink order. I felt like the forgotten flyer.

Delayed and cancelled flights were hard and very stressful, both ways!

The crew was quite good, they came by often with drinks or to collect trash. But what wasn't nice was the flight was over weigh and several people had to be rebooked. I was questioned whether I should have a seat when I was getting to it. The in-flight entertainment kept buffering and interrupting. And the route took the airplane through high winds which caused us a longer flight

Wasn’t on the flight due to Alaska cancellation…also after all the rerouting, I was going to be on a later flight that left SFO at 7:47pm, which meant an almost 6 hour layover. That same Hawaiian flight was delayed for another 2hours.

I had to cancel the flight because with a 3 hour delay for 'unexpected maintenance' in getting to LAX, I couldn't connect to an overseas flight that I had booked on Scandinavian Air.

The flight was CANCELED!!! Can’t get much more “poor” than that. I had to switch to American Airlines, add another layover and got home in Honolulu 4 hours later than I was supposed to be home. One bright spot was Josh with Alaska Airlines at SFO. He got me on a United Flight that got me home a few hours before I would have. Without him I would have gotten home almost 7 hours after my originally scheduled flight.

Canceled my flight within 24 hours, causing me arriving home midnight. Will never book Hawaiian airlines anymore

I like Hawaiian, it was great that they had good internet connection across the Pacific Ocean, thanks to Star Link satellites. The seating was comfortable, ( I was in economy ). Maybe I missed it, but I only got offered a beverage once. It was a nonstop flight KOA to SMF. I would take it again next time I go that way.

I always love flying Hawaii and I have nothing to add

Previously flown Hawaiian Airlines on similar routes, I found Alaska Airlines to be noticeably more comfortable. The seats on Alaska Airlines provided better support and cushioning, which made a significant difference on the long flight to the islands. When you’re spending 5-6 hours in the air, seat comfort really matters, and Alaska Airlines delivered where it counts. After comparing both carriers, I’ve decided to book with Alaska Airlines for all my future Hawaii trips. The superior seat comfort alone makes it worth choosing Alaska over Hawaiian Airlines. If you’re planning a trip to Hawaii and prioritizing comfort, I’d recommend giving Alaska Airlines a try. You won’t be disappointed. Highly recommended for Hawaii travel!

It was nice to have gotten up upgraded to first class with a meal on a three hour flight

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 needs to step up their game. Delayed flight leaving Seattle, San Francisco. Older aircraft, not very comfortable.

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.

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.

I enjoyed the extra leg room compared to other airlines. The first stewards made my daughter’s birthday special by giving her an extra snack. Then the last one coming home from Chicago to Appleton made our night really enjoyable Thanks for making our trip enjoyable

It was good..clean, comfy seat. Friendly warm welcoming crew. Was able to check my cabin luggage at the gate which I was able to pickup in a decent time from baggage claim. The app gave all updates from delays to baggage claim info. Overall smooth flight.

It was a typical flight. We had a delay which seems to be the normality now. And we had no in flight service due to conditions.

After we landed we sat on the tarmac for 1.5 hours waiting to get to our gate. Ridiculous.

Terrible. Flight delayed for more than 8 hours with only a $12 meal voucher provided for the inconvenience. The airplane did not have breaks on arrival yet they still made us go through the motions and board on time knowing we could not take off then sit for 40+ minutes before having to get of the time. A complete waste of my time. I cannot believe they can stay business with these shenanigans. I’ll avoid this company like the plague moving forward as the lack of accountability is disgraceful.

This was the best 2 flights I have had with American out of SGF. Great crew both flights.

Excellent - explanations were clear staff was nice and flight was comfortable

Lost bag and 2 days no word leaving for cruise no clothes or stuff

Any flight to ORD after about 2pm this summer has been challenging. Flight was delayed getting in (coming from ORD) and that led to it not leaving before a ground stop due to lightening before they could fuel the plane, and so forth. They made up some time but we were still late in arriving at ORD, and that led to missed connections.

Food was ok, but not as good as I have had before on AA.

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

Information on your arrival and departure airports