$59 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 5/28. 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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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 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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Best Illinois Flight Deals from Seattle

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours

Chicago
Chicago1 stop$143
Moline
Moline1 stop$372
Peoria
Peoria1 stop$271
Bloomington
Bloomington1 stop$351
Champaign
Champaign1 stop$320
Springfield
Springfield1 stop$229
Decatur
Decatur1 stop$374
St. Louis
St. Louis1 stop$189
Paducah
Paducah3 stops$647
Chicago
Chicago1 stop$143
Moline
Moline1 stop$372
Peoria
Peoria1 stop$271
Bloomington
Bloomington1 stop$351
Champaign
Champaign1 stop$320
Springfield
Springfield1 stop$229
Decatur
Decatur1 stop$374
St. Louis
St. Louis1 stop$189
Paducah
Paducah3 stops$647

Cheap Flights from Seattle to Illinois

 
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.

Recent round-trip flight deals from Seattle to Illinois

Recommended round-trip deals departing in the coming months from the most popular airlines that fly from Seattle to Illinois.
Discover the best prices for you by selecting your travel dates on KAYAK.
 Logo
3:20 pm - 5:25 amSEA-ORD
12h 05m1 stop
 Logo
10:00 am - 12:25 pmORD-SEA
4h 25mnonstop
Wed, May 28 - Sat, May 31
 Logo
3:20 pm - 5:25 amSEA-ORD
12h 05m1 stop
 Logo
6:00 am - 8:27 amORD-SEA
4h 27mnonstop
Wed, May 28 - Fri, May 30
Alaska Airlines Logo
12:40 pm - 6:55 pmSEA-ORD
4h 15mnonstop
Alaska Airlines Logo
7:51 pm - 10:30 pmORD-SEA
4h 39mnonstop
$156Alaska Airlines
Find Deal
Wed, Jun 4 - Wed, Jun 11
Alaska Airlines Logo
12:40 pm - 6:55 pmSEA-ORD
4h 15mnonstop
Alaska Airlines Logo
6:00 am - 8:27 amORD-SEA
4h 27mnonstop
$157Alaska Airlines
Find Deal
Wed, Jun 4 - Wed, Jun 11
Delta Logo
5:50 pm - 11:59 pmSEA-ORD
4h 09mnonstop
Delta Logo
7:09 am - 9:45 amORD-SEA
4h 36mnonstop
$169Delta
Find Deal
Tue, Jun 3 - Wed, Jun 11
American Airlines Logo
12:05 am - 6:05 amSEA-ORD
4h 00mnonstop
American Airlines Logo
7:25 am - 10:04 amORD-SEA
4h 39mnonstop
$170American Airlines
Find Deal
Mon, Jun 9 - Tue, Jun 17
Delta Logo
3:30 pm - 9:35 pmSEA-ORD
4h 05mnonstop
Delta Logo
6:50 pm - 9:37 pmORD-SEA
4h 47mnonstop
$174Delta
Find Deal
Fri, Jul 4 - Wed, Aug 13
United Airlines Logo
7:05 am - 5:10 pmSEA-ORD
8h 05m1 stop
United Airlines Logo
7:10 am - 9:43 amORD-SEA
4h 33mnonstop
$175United Airlines
Find Deal
Tue, Aug 19 - Tue, Aug 26
United Airlines Logo
5:18 pm - 11:23 pmSEA-ORD
4h 05mnonstop
United Airlines Logo
7:00 am - 2:00 pmORD-SEA
9h 00m1 stop
$180United Airlines
Find Deal
Tue, May 13 - Tue, May 20
American Airlines Logo
2:20 pm - 8:30 pmSEA-ORD
4h 10mnonstop
American Airlines Logo
7:35 am - 10:15 amORD-SEA
4h 40mnonstop
$200American Airlines
Find Deal
Wed, May 21 - Mon, May 26
Useful Info

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?

The cheapest price for flight routes found by users searching on KAYAK in the last 2 weeks for round-trip flights from Seattle to Illinois.

The cheapest ticket to Illinois from Seattle found in the last 72 hours was to Chicago, at $169 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 $169.

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.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 1 stop layover the cheapest option at $428 on average.

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 $223 (return) on average. On the other hand, the most expensive months are December and July, when the average cost of round-trip tickets is $382 and $348 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 Thursday, 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. For the absolute cheapest price, our data suggests you should book 6 weeks before departure.


Good to know

Low seasonJanuary
High seasonJuly
Cheapest flight$59
Best time to beat the crowds with an average 25% drop in price.
Most popular time to fly with an average 14% increase in price.
Flight from Seattle to Chicago O'Hare Airport

Flights from Seattle to Illinois: the best tips from KAYAK users

Insights shared by verified travelers who flew the route from Seattle to Illinois 
Verified travelerFlew with Alaska AirlinesSEA-ORDOct 2024
Alaska airline has best boarding and baggage policy.
ShirleyFlew with Alaska AirlinesSEA-ORDJun 2024
I generally fly United or Delta out of South Bend, IN into Seattle or wherever I'm going. I have no issues with Alaska. I only use Alaska when flying with my family from the Seattle area back to Chicago O'Hare and then we drive to SW Michigan where I live. Alaska Airlines has a beautiful new terminal at SeaTac as well. A good airline. I do like planes that have screens on the back of the seats.
Verified travelerFlew with United AirlinesSEA-ORDJul 2024
Budget if you’re planning on shopping for meals or souvenirs at Sea-Tac, it’s not cheap.
Verified travelerFlew with Alaska AirlinesSEA-ORDJun 2024
Bring books and earplugs for the four hour flight and enjoy Chicago!

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 $291 on average. Morning departures are around 69% 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 $491.

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 $163 one-way - $288 round-trip

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 9968 reviews
8.2Boarding
7.1Entertainment
8.5Crew
7.9Comfort
7.1Food
Airline reviews

I made a mistake. Read what I wrote in the flight from Dulles to SEA. The negative experience was from SEA to BOI. Total garbage. Wont do it again.

2.0 MediocreAnonymous, Apr 2025SEA - BOI
Read more Alaska Airlines reviews

I made a mistake. Read what I wrote in the flight from Dulles to SEA. The negative experience was from SEA to BOI. Total garbage. Wont do it again.

Need to get on train for second flight it’s much nicer when all the gates are together for obvious reasons

Cramped, crowded aircraft. Poorly organized boarding. Tasteless crackers to eat. 40 minutes late. A standard US air travel experience.

Would not mind having movie options an available like Delta, but is not necessary. Did not have food, so cannot appropriately rate that section.

Three hour flight so snacks and basic drinks unless you pre buy as usual. Didn’t do my emtertainment as was tired after 23 hours of travel. You have to use your own device on US flights if travelers aren’t aware so if you only use your cell phone that can be small. Crew are great.

Awful. We got the last seats and they don't recline. We've been on this horrible journey since 6am and won't get to our destination almost a full day later. Oh and no food, either. Never again.

An uneventful flight is a good experience although one of the pilots gauges wasn’t working right so we had a half hour delay—no one can foresee that.

Plane was delayed and got me in past bedtime. But more importantly, my tsa precheck number wasn’t on my ticket so had to deal with the general line. Oh well, guess the delay helped that situation.

It was as good as flying can be, which is still very uncomfortable. Clean new aircraft, great crew.

Everything was good. The flight attendants were great. I was disappointed that there wasn’t any screens on the back of the seats to watch movies, tv, etc. I only had my phone to watch movies on.

It is southwest seat was ok. Not the most comfortable seat

I’ve always loved Southwest. No issues at all. I was flying standby and the gate agent was extremely friendly and helpful. Boarding was smooth and I was able to get a window seat in the emergency exit row. Crew was fantastic! They were very professional and accommodating. We had to divert from our destination due to weather but the flight crew kept everyone at ease and informed us of all pertinent information. Excellent flight

The price of the tickets isn't matching the flight experience. No matter how long the flight is, you're only getting pretzels. The flight attendants looked unkept and over it.

Plz don't take away free bags and free seating

The seats were a bit cramped and worn, but otherwise okay.

I would have liked to arrive on time - not 5 hours late!

After a 3 hour layover in Denver my flight was delayed over 5 hours! No explanation; no assistance; no offer to provide compensation; no one at Southwest was willing to offer any assistance. 8 hours in the Denver airport - ridiculous!

It was a perfect flight in all aspects! Both legs!

Only one drink pass through the cabin for a 4 hour flight. Quite rough and bumpy landing.

Boarding process, crew were good. But the seats were so uncomfortable that was all I could focus on. I literally had to sit forward so that all 3 of us could fit in row. I will try to avoid Southwest in the future for any flights over 60 minutes.

Delta is my preferred airline. I've traveled with them for years. On time in most cases, good communication, easy to use app. Most planes are pretty nice. I was on a CRJ 700/900 however, which was pretty badly aged inside and needed a refresh. No infotainment, unreliable wifi, best to download before boarding or bring a book. Food choices are really just snacks on this flight, nice variety but about what you'd expect. Great staff and prompt in departure and early arrival too. Overall quite satisfied.

Crew was friendly Love the entertainment in the seat head rest.

Delta flight was on time, seats were comfortable, and crew was nice.

This had nothing to do with Delta… The flights were on time and flawless. The service was excellent. We purchased seats in (aisle/middle) comfort plus since this was a cross country flight. Unfortunately, the woman seated at the window was 300+ pounds and, as might be expected, covered up about a third of the middle seat also. there was absolutely nothing that Delta could have done about that… I just don’t know what the answer should be. If you purchase a seat, you should should be able to use the entire seat and not just the portion that someone else is not sitting/oozing in. Disappointing…there should be something that could be done….I'm just not sure what solution could be.

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.

The worst part was I was NOT allowed in the lounge even though I was holding a first class ticket and have a premium American Express card. I have flown Business or First Class with many airlines. Delta is the ONLY one who does not extend this courtesy to anyone except people who hold the very expensive American Express card. As a result, I won’t fly Delta if I have any other choice.

A little bumpy ride . No food was being provided due the the turbulence. That was ok it was a short flight to my standards.

Simply outstanding. Their new lounge for Delta One customers is a cut above the rest.

The Dekta Rep that checked us in was great. She's very personable, pleasant, and can tell she enjoys her job.

The plane was old with small storage areas that had problems closing/latching and not enough storage for everyone, and worn, damaged seats. Service was great but feel a little unsafe on such well used planes.

Smooth flight. Boarding was chaotic. Could not hear the gate agent over the intercom. People were lined up in the wrong lines. Groups one and two were told to board through line one and group 3 through line 2. All very confusing. Once in the air, the flight was smooth. There was no entertainment option on this aircraft, even though it was a larger aircraft.

Overall poor for me I paid extra for seats with leg room and my regional flights exit row seats have less leg room then the others that's money that could have been saved and on my final flight home the flights air was not operating it was unbearably hot in the cabin I will be contacting United and filing a DOT complaint

There's just no way to sit fully upright and comfortably in these seats. There needs to be 2 more inches of room, and that's not something that only one person on the flight needs - the whole flight needs 2 more inches of room. If that means you sell 6 less seats, so be it. It's too close for anyone. Forcing people to pay for "premium" economy just to get "barely enough space to breathe" isn't really an answer to that.

The crew were very nice. The Chocolate is good and v there’s no entertainment. Thanks

The crew were very nice. I would have appreciated a pillow for comfort. I had a special meal that was sloppy, but the salad was great. Thanks

The plane was in Moline all night. Consequently, we assumed an on time departure at 8:15am. Unfortunately, and as is the normal case with United in Moline, we departed 2.5 hours late. When the crew came, it was discovered that there was very little heat in the plane. Seems this should have been checked hours before the crew arrived. Then when we boarded and the plane was to be de-iced, the United de-icing truck was not working! We awaited the American Airlines truck. All of this caused us to miss our connection in Chicago. My suggestion is never take United Airlines flight from Moline. We have been disappointed 80% of the time and have vowed to not take United again from Moline.

Flight was delayed two hours. No snacks and no tv screens. My bag got stuck in Chicago

The aircrew was solid, the flight was chill, I had no issues. The gate agent was not the best. I was trying to use a military bag upgrade to move my bag from under the seat to the overhead bins and he told me there’s no overhead bins on the plane, argued with me why booking put a military member in basic economy (I don’t really understand this) and made it an issue to even try to help me stating I’d have to call reservations to get a bag upgrade. When every other agent with United can add it at the gate, this man couldn’t be bothered.

They canceled our flight and left us stranded to figure it out

Everything was very good. Was able to change a make run flight leaving on direct earlier in the app -seamless!!! Well done

To start, I’d like to say that every American Airline personnel I interacted with on the ground, especially flight crew, was very friendly and did their best to help me out. Despite this, however, my experience with the airline was an entire mess. The 7:19 PM flight was heavily delayed due to weather, and pushed to 10:30 AM the next morning. Because of this, I had to spend the night inside of the airport. At some point later in the night, I got an email saying that the flight had been canceled. I called the support number, and the representative on the other line told me that the flight was still on and that I didn’t need to rebook. The next morning, no one came to the gate to open the door for the crew until almost 11 AM. By this time the flight crew had been waiting for over an hour, and they had called management to get someone to open the door for them multiple times. Around 11:30, the gate screen had changed to a different flight. I ended up buying a last minute ticket with Southwest airline just to get to Chicago, because the next flight with American wasn’t until 7:19 pm that day. Now, earlier that morning my suitcase had been sent ahead of me to ORD. I went to baggage claim to ask them if I could have my suitcase forwarded to where I was staying. The representative at SDF baggage claim said they could and put the claim in for me. As I was going back through TSA, I got an email that the airline had found my suitcase, but the next step was to send it BACK to SDF. I called the airline support number again, and I made it clear that my suitcase needed to stay in Chicago and to not come back to SDF. The representative told me that they would hold my suitcase at ORD and that it wasn’t going to be forwarded anywhere. Once I got there, I found that they had loaded my suitcase onto a plane to send it back to SDF. Thankfully, I had gotten to the baggage claim counter in time for them to put in a request to bring my suitcase back up. My refund with the airline is processing already, but because of this entire experience and miscommunication at every turn of the way, I will not book with American Airlines in the future.

The plane was late and then sat on the runway for almost 45 minutes before taking off.

Crew professional. Easy bag drop off. On time. Good entertainment.

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

Everything was great except it became so hot on the plane I couldn’t sleep on my red eye flight. It didn’t really cool down till we started descending.

Per usual, flight status, staff courtesy and professionalism were excellent

Everything was on time, we arrived early, everything worked well.

The only thing is if Wi-Fi is available after you land and taxi to the gate. It takes forever to get to the gate, and having the Wi-Fi continue would be great to bide the time at least 5 minutes before you arrive at the entrance. That is my only comment; otherwise, everything was good.

Had to wait on pilot and crew to depart and had to wait to arrive at the gate because they only had 2 crews working. Delays, delays....Planes just keep getting smaller and tighter and they nickle and dime for everything. When will an airline actually wake up and make flying more enjoyable?

Seating was horrible. Small seats. Access to flight information and extras very iser unfriendly. Kept losing internet after paying for it. Staff in madison was as unprofessional and unhelpful.

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