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Find cheap flights from Seattle to Illinois from $40

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 6/4. 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
Thu 6/27
Thu 7/4

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Best Illinois Flight Deals

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

Chicago
Chicago1 stop$157
Moline
Moline1 stop$483
Peoria
Peoria1 stop$427
Bloomington
Bloomington1 stop$766
Champaign
Champaign1 stop$876
Springfield
Springfield1 stop$742
St. Louis
St. Louis1 stop$150

Good to know

Low season

January

High season

June

Cheapest flight

$40
Best time to beat the crowds with an average 30% drop in price.
Most popular time to fly with an average 18% 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 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 $154 one-way - $323 round-trip
  • Morning departure is around 19% 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 1501 reviews
7.9Food
8.6Crew
8.2Comfort
8.4Boarding
8.0Entertainment
Airline reviews

Their announcement was not quite clear in Chinese. The rest is pretty good.

8.0 ExcellentYue, May 2024IAH - TPE
Read more about EVA Air reviews

Their announcement was not quite clear in Chinese. The rest is pretty good.

The hygiene of the bathrooms were terrible. Urine smells leaked out into the cabin and the seats were really tight, even for a petite woman like myself. Flight attendants did not go through the cabin enough to offer refreshments.

I was expecting that movie selection and food would have been better. Everything else was great.

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.

Fast and efficient boarding. Flight was on time. Service was very good for our long flight. First time flying with this airline and I would highly recommend.

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.

The plane from SNA wouldn’t start after 5 tries. The team gave me an option of flying direct from LAX and giving me a Lyft ride there! Perfect!

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.

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.

The CX617 from HK to BKK was delayed more than 1.5 hours.

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!

This was a red eye return, so I doubt there would be anyway to make it better. Other than adding beds.

Excellent host on board. Not so friendly check-in staff. Older plane with no food or entertainment due to short flight. Friendly captain and crew.

It took 66 hours to get from Seattle to Tel Aviv. As a minor, I was left for more than 12 hours in Toronto and Frankfurt without hotel and food vouchers. It took 5 layovers. It was insane and not okay

Flew SEA-CA, then CA-NRT. First flight was short but very uncomfortable, dirty, and had very small overhead storage space. The seats and fans were not cleaned and had visible dirt on them. Second flight was perfect.

My experience was pretty frustrating because the first leg of my flight on United (though booked through Air Canada) was delayed causing me to miss my connecting flight on Air Canada. This could have been an easy solve as there was a direct flight later that morning via Air Canada that they easily could have put me on which would have only gotten me to my destination 2 1/2 hours later but because United and Air Canada don’t seem to have good communication they gave me the run around both telling me to talk with the other which I did three times to no avail. I ended up taking the delayed flight and getting on a new connecting flight which ended up getting me to my destination 6 hours later and I missed the event I was planning to go to this evening.

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

Book cheap flights from Seattle to Illinois

Recent round-trip flight deals

9/4Wed
1 stopSpirit Airlines
29h 50mSEA-STL
9/9Mon
1 stopSpirit Airlines
19h 43mSTL-SEA
$150
6/11Tue
1 stop
6h 55mSEA-ORD
6/18Tue
nonstop
4h 34mORD-SEA
$157
7/24Wed
1 stopAlaska Airlines
8h 21mSEA-ORD
8/21Wed
nonstopAlaska Airlines
4h 34mORD-SEA
$170
6/10Mon
nonstopAlaska Airlines
4h 06mSEA-ORD
6/18Tue
nonstopAlaska Airlines
4h 37mORD-SEA
$179
10/1Tue
1 stopAmerican Airlines
7h 42mSEA-STL
10/8Tue
1 stopAmerican Airlines
8h 37mSTL-SEA
$195
6/12Wed
nonstopUnited Airlines
3h 58mSEA-ORD
6/19Wed
nonstopUnited Airlines
4h 38mORD-SEA
$206
6/10Mon
nonstopDelta
3h 58mSEA-ORD
6/16Sun
nonstopDelta
4h 30mORD-SEA
$209
10/4Fri
1 stopAmerican Airlines
8h 43mSEA-STL
10/8Tue
1 stopAmerican Airlines
8h 37mSTL-SEA
$211
10/2Wed
1 stopDelta
9h 27mSEA-STL
10/7Mon
1 stopDelta
7h 00mSTL-SEA
$221
6/11Tue
1 stopUnited Airlines
10h 12mSEA-STL
6/19Wed
1 stopUnited Airlines
8h 05mSTL-SEA
$316

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Recent one-way flight deals

6/4Tue
1 stopSpirit Airlines
13h 25mSEA-STL
$40
9/10Tue
2 stopsSpirit Airlines
15h 46mSEA-STL
$59
8/27Tue
nonstopAmerican Airlines
4h 09mSEA-ORD
$75
10/19Sat
1 stopAmerican Airlines
8h 05mSEA-STL
$97
7/10Wed
nonstopDelta
3h 56mSEA-ORD
$105
9/8Sun
1 stopAlaska Airlines
7h 15mSEA-ORD
$114
7/12Fri
1 stopDelta
8h 25mSEA-STL
$124
6/26Wed
nonstopAlaska Airlines
3h 55mSEA-ORD
$129
8/25Sun
nonstopUnited Airlines
4h 01mSEA-ORD
$131
6/24Mon
nonstopUnited Airlines
3h 58mSEA-ORD
$132

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Last minute flights from Seattle to Illinois

Last minute flight, train and bus deals

6/1Sat
multi-stopFrontier
22h 24mSEA-STL
6/3Mon
multi-stopFrontier
13h 34mSTL-SEA
$185
6/1Sat
multi-stopFrontier
22h 24mSEA-STL
6/3Mon
multi-stopFrontier
18h 53mSTL-SEA
$190
5/29Wed
multi-stopDelta
8h 30mSEA-STL
6/3Mon
multi-stopDelta
7h 09mSTL-SEA
$276
5/29Wed
multi-stopAmerican Airlines
9h 13mSEA-STL
6/2Sun
multi-stopAmerican Airlines
7h 57mSTL-SEA
$356
5/31Fri
multi-stopAmerican Airlines
7h 20mSEA-STL
6/2Sun
multi-stopAmerican Airlines
7h 28mSTL-SEA
$357
6/1Sat
nonstopDelta
4h 10mSEA-ORD
6/12Wed
nonstopDelta
4h 44mORD-SEA
$394
6/2Sun
multi-stopAlaska Airlines
6h 55mSEA-ORD
6/10Mon
nonstopAlaska Airlines
4h 35mORD-SEA
$403
5/30Thu
multi-stopUnited Airlines
7h 43mSEA-STL
6/2Sun
multi-stopUnited Airlines
6h 52mSTL-SEA
$407
5/29Wed
multi-stopUnited Airlines
9h 10mSEA-STL
6/2Sun
multi-stopUnited Airlines
6h 52mSTL-SEA
$412
5/29Wed
nonstopAlaska Airlines
4h 04mSEA-ORD
7/4Thu
multi-stopAlaska Airlines
6h 25mORD-SEA
$414

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Seattle - Illinois Flights