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Find cheap flights from Seattle to Illinois from $42

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 5/21. 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
0 bags
Sat 6/1
Sat 6/8

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Best Illinois Flight Deals

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

Chicago
Chicagononstop$139
Moline
Moline1 stop$516
Peoria
Peoria1 stop$457
Bloomington
Bloomington1 stop$457
Champaign
Champaign1 stop$573
Springfield
Springfield1 stop$564
Paducah
Paducah2 stops$622
St. Louis
St. Louis1 stop$231

Good to know

Low season

January

High season

August

Cheapest flight

$42
Best time to beat the crowds with an average 16% drop in price.
Most popular time to fly and prices are also 8% lower on average.
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 to Illinois from Seattle 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 to Illinois with an airline and back to Seattle 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 to Illinois from Seattle up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

See more FAQs

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 $169 one-way - $294 round-trip
  • Morning departure is around 5% more expensive than an evening flight, on average*.
*Average of the lowest prices shown in KAYAK’s search results for departures within the next 30 days

Top 5 airlines serving from Seattle to Illinois

 
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.
8.3
EVA AirOverall score based on 1542 reviews
8.2Comfort
8.4Boarding
8.6Crew
8.0Entertainment
8.0Food
Airline reviews

The type of the food requested (Asian vegetarian) was not properly met with. They have very limited snack items that may compensate for the main meals.

8.0 ExcellentAnonymous, Apr 2024TPE - JFK
Read more about EVA Air reviews

The type of the food requested (Asian vegetarian) was not properly met with. They have very limited snack items that may compensate for the main meals.

The quality of the food is pretty good. Thank you, EVA Air.

Pleasant, comfortable, and entertaining. All told, ZERO issues with it. And sadly, so far the flight was WAY more comfortable than the hellhole that is "Lambug Beach Resort" at Badian Beach!

Pleasant crew. Very long flight, a bit uncomfortable at times being seated, but not too bad.

No ice for the drinks. Only gave a half a cup of your beverage. Not enough water. I got very dehydrated.

Eva is one of the top airlines in Asia... but often are over priced. Finally found a reasonable rate.

My original flight was rescheduled & EVA did a good job rescheduling my flight & connecting flight.

Polite hard working crew. No complaints really. Meals were not to my liking.

Everything was fantastic! The crew really went above and beyond to make it a great flight. I felt cared for with EVA.

t and I Flight crew did excellent job taking care of us and feeding us and staying professional. The boarding was delayed by an hour and then extra security measures were taken. No real explanation except for they said it was more of a maintenance dey

Had a broken tray in business class. Crew just shrugged it off.

Everything was great except for the seat. The backrest would not stay in the upright position.

public website still broken for years randomly blocking browsers with privacy options active after loading a page maybe once. check-in on laptop was almost impossible but eventually randomly worked. had to print pass at airport since couldn't get back in to load digital pass on mobile firefox or chrome. red eye flight so smooth onboarding, plenty of room to spread out, easy offboarding. onboard wifi instructions mention vpn can cause problems connecting but fails to also mention private dns. no printed or built in menu list, seems weird to require personal device to point at qr code link for menu which does not even allow direct ordering. people with health condition risk related dietary restrictions trying to avoid for example cholesterol and sugar are left guessing what they can order either way without nutritional info highlights (cranberry juice was minute maid cocktail with as much suger as typical can of soda). tap to pay wasn't working and always seems sketchy to manually enter card info. good movie variety, so limited tv was okay.

Bag drop off was slow and annoying. Only 2 agents at the entire delta desk, and no one directing traffic for what line to be in, many confused people slowed down the process. Boarding was fine. Seats in Delta comfort plus were fine. Snacks were great! Definitely a bonus. The entertainment system was awful — old, slow, not responsive, and completely unable to play games due to some kind of error. But on the other hand, thank you to Delta for the free WiFi. That made it better.

Flight diverted in SD. Later take off in Seattle by 1.3hrs

Mi primera conexión se retrasó por lo cual perdí mi segunda conexión la cual salió adelantada

Crew was not friendly when I went to request a seat change.

There were choices for the snacks. Good choices and tasty lunch and breakfast as well.

The flight crew was amazing. I’m very tall and they moved me to an exit row unsolicited!!! Amazing service.

The boarding process was terrible especially with an indirect flight Chicago to Seattle to San Diego was terrible talking about we overbooked a flight idk if I’d take this airline ever again we got off our flight from Chicago to Seattle and we traveled for business and they told us our connecting flight was over booked and their was no seats asking people to take a delayed next flight and they don’t tell anyone coughing to wear masks seats 30A-B were terrible during the flight no one wants to sit next to people coughing all around I don’t want to be sick traveling for work or get sick anytime it’s very upsetting the staff doesn’t take this stuff serious to tell them to wear masks when they see people coughing and sneezing

I was told we'd have a hot breakfast option in first class, so I chose not get a hot breakfast. It was a very strange meal, but the fresh fruit was very good quality. Service was excellent from ORD to ELP. No service from MBS to ORD, not even water. However, when flying American from FNT to ORD, which is a shorter flight, they at least pass out snacks and offer water.

The delays (5 hrs) were a comedy of errors, and the multiple safety issues encountered were very concerning.

The flight was delayed instead of leaving at 11 it left at 12.20

United WiFi is consistently unusable (it can take 10 mins to load a single web page). If you need Wifi to do work, be prepared to lose half a day of productivity.

Good movies, iffy pay WiFi, food ok- on time though and that was great!

Awful…flight was delayed more than 12hrs, missed all connections to Fort Wayne, IN, had to get flight to another city 2 hours from my destination, flight was again delayed by 40 mins because they did not have enough fuel, again missed a connection, finally arrived in Indiana at 11pm…but before my 2 hour drive home, ay, no Five That Our Luggage Never Made On The plane and Still In Chicago

Boarding was friendly and quick. While the plane model was older with no live tv, the entertainment was full of movies and tv shows. All food was available. Pilots were very communicative with status of the flight. Flight landed on time.

Flight was delayed by over an hour and gate checked bags took 15 minutes to be delivered to the jet bridge.

The Palm Springs to Chicago O’Hare was on Time and Palm Springs airport is easier navigate. As our connection was only an approximately 50 minutes, we asked staff for insights for the Chicago airport in terms of transferring into the other terminal from which our flight left, and they were unhelpful. However, the United App was very helpful in terms of notifications and even providing directions. The Chicago to Detroit flight was significantly delayed which we all know does happen. However, there were very few updates or notifications as to why this was happening when we would actually arrive. It took nearly 30 minutes for bags to make it to baggage claim. We arrived nearly 1 hour late on a 40 minute flight.

Flight cancelled due to fog. No other flights available for 36 hours. Directed by United to book passage on another carrier, and submit receipts for reimbursement. Did that. United now states they will not reimburse. Currently out 2 grand.

This flight is frequently delayed. The connections seemingly are more frequently delayed. I’ve missed connections as a result twice on the same route to charlotte then Charleston. Final destination arrival has been the next day, twice in a row. No pilots, no crew. Too many excuses. Unfortunately, my days with American are over.

Entertainment was okay not because anything was wrong but it is a short flight so having no wifi is annoying but understandable. Crew was outstanding as usual

Those seats were way too narrow. I had the middle seat, one person was a very skinny person and we still couldn’t avoid touching each other anytime one of us moved. The other person was larger and we were basically sitting in each others lap the entire flight. There was zero entertainment. The flight was long enough to justify tvs, but no. Gotta sit there in your infant seat and twiddle your thumbs.

Flight was fine. It took an unusually long time to have baggage delivered to the carousel in ORD.

Average - flew with Jet Blue internal and it was far more comfortable and better food and entertainment. Notable difference

The flight got canceled due to mechanical issues, and he to be rebooked and missed my appointments for that day

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.

The only problem experienced was a ground stop in Chicago due to weather. But the crew handled everything professionally. They prioritized rebooking those passengers who had connecting flights and then deplaning the other passengers. When the hold was lifted, they efficiently re-boarded all the passengers so that we could depart before our departure limit expired.

I had the exit seat with all the leg room I could ask for. Great!

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.

I was appalled to have to pay for just a regular seat when I went to book 24 hrs before my flight! Because it was only an hour flight I didn’t choose a seat from Grand Junction to Denver, but I did for Toronto and had to pay just to choose a regular available seat! In my 60+ years of flying this was the first time I have heard of this. Also, allowing people to bring on “huge “ suitcases, not carry on size, but much bigger, and then a large pack pack stuffed. So they take up all the room in the overhead bins and if we are later boarding, there is no room so we have to check our small carry on. I have already paid for and checked in one bag! I certainly will not choose to fly with United again unless it is the “only” airline available!

Ontime boarding. Almost 1 hour take off delay. We could have boarded slightly later since the pilots were in traffic

Flight was delayed, I had to put my luggage all the way in the back! They served only a beverage no snack on the way in Air Canada, definitely not a good first impression.

Fresh fuit or veg snacks would be so great, but there are two good restaurants in Denver airport. Try Etais UDIS or Freshens DIA for nutritious delicious pita sandwiches/ donairs and crepes in Freshens.

Crowded plane but it flew on time and had friendly staff

This was the first AC flight in a long time that we experienced no delays or frustrations. The gate attendant was extremely polite and accommodating to my husband who has Parkinson’s disease which made boarding extremely stress free. Flight departed ON TIME and was a smooth ride. If only all my AC experiences could be like this.

The Air Canada agent was very helpful helping with my luggage and cat carrier when I went there instead of United.

Lost my bag. My first ever flight with them that they forced me to gate check my bag on, due to them having a 30 year old plane with small carry on bins, and they lost my bag. Never again.

United force you to download their App to do the check-in.

I liked Seattle but nothing air Canada did there was any good at all neither was kayak as when I purchased my flights the price I purchased at was not what kayak charged to my card and there has been no responses to my emails ....

Book cheap flights from Seattle to Illinois

Recent round-trip flight deals

5/25Sat
nonstop
4h 04mSEA-ORD
6/4Tue
1 stop
11h 40mORD-SEA
$139
5/29Wed
1 stopSpirit Airlines
10h 20mSEA-ORD
6/4Tue
1 stopSpirit Airlines
11h 40mORD-SEA
$140
5/29Wed
nonstopAlaska Airlines
4h 04mSEA-ORD
6/5Wed
nonstopAlaska Airlines
4h 35mORD-SEA
$149
9/18Wed
1 stopUnited Airlines
9h 45mSEA-ORD
9/24Tue
nonstopUnited Airlines
4h 33mORD-SEA
$171
10/1Tue
nonstopDelta
3h 58mSEA-ORD
10/3Thu
nonstopDelta
4h 39mORD-SEA
$176
5/29Wed
nonstopAlaska Airlines
4h 06mSEA-ORD
5/30Thu
nonstopAlaska Airlines
4h 35mORD-SEA
$179
5/29Wed
nonstopDelta
4h 05mSEA-ORD
6/4Tue
nonstopDelta
4h 43mORD-SEA
$189
6/7Fri
nonstopUnited Airlines
3h 58mSEA-ORD
6/16Sun
nonstopUnited Airlines
4h 37mORD-SEA
$245
6/6Thu
1 stopAmerican Airlines
8h 12mSEA-ORD
6/9Sun
1 stopAmerican Airlines
7h 22mORD-SEA
$266
5/6Mon
1 stopAmerican Airlines
9h 48mSEA-STL
5/8Wed
1 stopAmerican Airlines
9h 35mSTL-SEA
$274

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Recent one-way flight deals

5/21Tue
1 stopSpirit Airlines
11h 06mSEA-STL
$42
5/14Tue
1 stopSpirit Airlines
11h 06mSEA-STL
$43
5/25Sat
nonstopDelta
4h 05mSEA-ORD
$75
9/25Wed
1 stopUnited Airlines
9h 45mSEA-ORD
$80
10/1Tue
1 stopAmerican Airlines
9h 32mSEA-STL
$103
7/16Tue
nonstopDelta
4h 05mSEA-ORD
$105
6/10Mon
1 stopAlaska Airlines
6h 55mSEA-ORD
$107
5/22Wed
1 stopAmerican Airlines
9h 13mSEA-STL
$112
5/23Thu
1 stopAlaska Airlines
6h 55mSEA-ORD
$114
8/25Sun
nonstopUnited Airlines
4h 05mSEA-ORD
$141

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Last minute flights from Seattle to Illinois

Last minute flight, train and bus deals

5/7Tue
multi-stopFrontier
12h 03mSEA-MDW
5/9Thu
multi-stopFrontier
22h 31mMDW-SEA
$172
5/7Tue
multi-stopFrontier
25h 21mSEA-ORD
5/9Thu
multi-stopFrontier
24h 36mORD-SEA
$188
5/4Sat
multi-stopAmerican Airlines
10h 29mSEA-STL
5/11Sat
multi-stopAmerican Airlines
8h 21mSTL-SEA
$273
5/6Mon
multi-stopAmerican Airlines
9h 48mSEA-STL
5/8Wed
multi-stopAmerican Airlines
9h 35mSTL-SEA
$274
5/3Fri
multi-stopDelta
6h 21mSEA-STL
5/6Mon
multi-stopDelta
7h 44mSTL-SEA
$276
5/4Sat
multi-stopUnited Airlines
11h 54mSEA-STL
5/11Sat
multi-stopUnited Airlines
7h 26mSTL-SEA
$305
5/4Sat
multi-stopUnited Airlines
11h 54mSEA-STL
5/11Sat
multi-stopUnited Airlines
7h 26mSTL-SEA
$309
5/7Tue
nonstopDelta
4h 11mSEA-ORD
5/9Thu
nonstopDelta
4h 30mORD-SEA
$379
5/6Mon
nonstopAlaska Airlines
3h 59mSEA-ORD
5/15Wed
nonstopAlaska Airlines
4h 34mORD-SEA
$394
5/6Mon
multi-stopAlaska Airlines
7h 00mSEA-ORD
5/15Wed
nonstopAlaska Airlines
4h 34mORD-SEA
$403

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Seattle - Illinois Flights

Departure:

Seattle (SEA)United States

Return flight deals:

Illinois - Seattle

Cabin classes:

$478
$373
$406
$114