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$62+ Cheap flights from Illinois to Seattle (SEA)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 12/10. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SEA
oct. 11 — oct. 181
sam. 10/11
sam. 10/18
1 adult, Economy
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Cheap flight deals from Illinois to Seattle

Keep the following information in mind while searching for Illinois to Seattle flight deals. Data was last updated septembre 11, 2025.

Round-trip from

$176
(Southwest)

One-way from

$62
(Southwest)

Popular in

December

Cheapest in

February

Average price

$236

Good round-trip deal

$189 or less

Good one-way deal

$94 or less
From Illinois to Seattle/Tacoma Intl
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One-way flight from Illinois to Seattle/Tacoma Intl
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Highest demand for flights based on searches. 5% potential increase in price ($15 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($7 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from Illinois to Seattle/Tacoma Intl.
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Price to beat on a one-way flight from Illinois to Seattle/Tacoma Intl.
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Find flight deals from Illinois to Seattle

Cheapest flights from Illinois to Seattle
Explore the most affordable flight options available from Illinois to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on septembre 11, 2025.

This Alaska Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 11/246:00 amORD - SEA
Nonstop4h 37mAlaska Airlines
jeu. 11/2710:53 amSEA - ORD
Nonstop4h 13mAlaska Airlines
Deal found 9/11$176
This United Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sam. 10/114:10 pmORD - SEA
Nonstop4h 39mUnited Airlines
sam. 10/187:37 pmSEA - ORD
1 stop8h 18mUnited Airlines
Deal found 9/11$177
This Alaska Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mar. 11/182:05 pmORD - SEA
1 stop6h 43mAlaska Airlines
jeu. 11/2710:53 amSEA - ORD
Nonstop4h 13mAlaska Airlines
Deal found 9/11$179
This Kiwi.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dim. 10/126:50 amORD - SEA
1 stop26h 43mMultiple Airlines
mer. 10/155:50 pmSEA - ORD
Nonstop4h 09mMultiple Airlines
Deal found 9/10$180
This Booking.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 10/206:24 pmMDW - SEA
1 stop19h 43mFrontier
jeu. 10/231:02 pmSEA - MDW
1 stop9h 34mFrontier
Deal found 9/10$181
This Hawaiian Airlines deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mer. 10/16:20 amORD - SEA
Nonstop4h 32mHawaiian Airlines
ven. 10/312:17 amSEA - ORD
Nonstop4h 07mHawaiian Airlines
Deal found 9/10$181
This Alaska Airlines deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
ven. 10/176:00 amORD - SEA
Nonstop4h 27mAlaska Airlines
dim. 10/1912:17 amSEA - ORD
Nonstop4h 07mAlaska Airlines
Deal found 9/11$182
This Booking.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jeu. 11/612:30 pmMDW - SEA
1 stop25h 43mFrontier
dim. 11/92:22 pmSEA - MDW
1 stop19h 08mFrontier
Deal found 9/10$183
This Priceline deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 10/206:50 amORD - SEA
1 stop7h 17mFrontier
jeu. 10/231:02 pmSEA - ORD
1 stop8h 51mFrontier
Deal found 9/10$183
This Delta deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sam. 10/2511:10 amMDW - SEA
1 stop9h 13mDelta
ven. 10/3111:55 pmSEA - MDW
1 stop8h 35mDelta
Deal found 9/10$184
This Trip.com deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
dim. 10/266:00 amORD - SEA
Nonstop4h 40mHawaiian Airlines
dim. 11/23:31 pmSEA - ORD
Nonstop4h 09mHawaiian Airlines
Deal found 9/11$184
This Southwest deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mer. 10/19:05 pmMDW - SEA
Nonstop4h 30mSouthwest
mer. 10/89:10 amSEA - MDW
Nonstop4h 00mSouthwest
Deal found 9/9$185

Cheapflights Fare Finder

 
Customize your flight search to find flights from Illinois to Seattle that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated septembre 11, 2025.
Use the filters below to find and compare flights from Illinois to Seattle that are best for you.

Fly from

Illinois

Fly to

Seattle

Route

Depart

Return

Price

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

ven. 10/3

2:07 pm-8:35 pm

1 stop8h 28m

Seattle/Tacoma Intl

mar. 11/4

6:15 pm-12:24 am

Nonstop4h 09m

$180

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

sam. 11/22

6:15 pm-11:10 pm

1 stop6h 55m

Seattle/Tacoma Intl

jeu. 11/27

10:53 am-4:56 pm

Nonstop4h 03m

$183

ChicagoSeattle

MDW - SEA

MDWSEA

Chicago Midway

mar. 10/21

3:25 pm-10:45 pm

2 stops9h 20m

Seattle/Tacoma Intl

sam. 10/25

5:00 am-4:25 pm

2 stops9h 25m

$191

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

ven. 10/3

1:01 pm-3:35 pm

Nonstop4h 34m

Seattle/Tacoma Intl

sam. 10/4

12:17 am-6:24 am

Nonstop4h 07m

$191

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

jeu. 9/25

7:10 am-9:45 am

Nonstop4h 35m

Seattle/Tacoma Intl

mer. 10/8

5:55 pm-11:50 pm

Nonstop3h 55m

$194

ChicagoSeattle

MDW - SEA

MDWSEA

Chicago Midway

mar. 10/7

7:00 pm-11:45 pm

1 stop6h 45m

Seattle/Tacoma Intl

mer. 10/8

9:10 am-3:10 pm

Nonstop4h 00m

$194

ChicagoSeattle

MDW - SEA

MDWSEA

Chicago Midway

lun. 11/3

10:50 am-1:25 pm

Nonstop4h 35m

Seattle/Tacoma Intl

mer. 11/12

10:50 am-10:55 pm

2 stops10h 05m

$197

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

ven. 10/24

8:00 am-10:40 am

Nonstop4h 40m

Seattle/Tacoma Intl

lun. 10/27

12:20 am-6:22 am

Nonstop4h 02m

$207

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

ven. 10/24

7:37 am-10:15 am

Nonstop4h 38m

Seattle/Tacoma Intl

mar. 10/28

5:55 pm-11:50 pm

Nonstop3h 55m

$207

ChicagoSeattle

MDW - SEA

MDWSEA

Chicago Midway

sam. 11/15

2:05 pm-8:00 pm

1 stop7h 55m

Seattle/Tacoma Intl

dim. 11/16

6:35 am-12:30 pm

Nonstop3h 55m

$207

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/11

Showing 1-10 of 60 results
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Best time to book a flight from Illinois to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from Illinois with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

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

What is the cheapest month to book a flight from Illinois to Seattle?

Currently, January is the cheapest month in which you can book a flight from Illinois to Seattle (average of $238). Flying from Illinois to Seattle in June is currently the most expensive (average of $388). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from IL to SEA?

Find hourly flight availability from Illinois to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated septembre 11, 2025.

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Illinois to Seattle as you normally would.

Weekly flight availability from Illinois to Seattle

Explore weekly flight availability from Illinois to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated septembre 11, 2025.

The most flights from USIL to SEA are scheduled on a Thursday (58 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (36 on average).

Related info for your journey

Find useful and relevant information for your journey from Illinois to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Seattle from Illinois?

    Seattle/Tacoma Intl (SEA), located 11.4 mi from the city center, is the airport you fly into when you book flights from Illinois to Seattle.

  • How long is the flight from Illinois to Seattle?

    Departing from Illinois to Seattle will take you 6h 55m. The distance between Illinois and Seattle is about 1715 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

  • What are the cheapest airlines to fly from Illinois to Seattle one-way?

    The cheapest airlines for a one-way flight from Illinois to Seattle are Southwest ($62), Delta ($89), and United Airlines ($96).

  • What are the most popular routes from Illinois to Seattle?

    The most popular route from Illinois to Seattle is Chicago O'Hare Intl - Seattle/Tacoma Intl. You may also consider Lambert-St Louis - Seattle/Tacoma Intl or Chicago Midway - Seattle/Tacoma Intl.

  • What are the most reliable airlines from Illinois to Seattle?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Illinois to Seattle on time: Delta (87%), Air France (87%), KLM (83%).

  • What are the cheapest flights from Illinois to Seattle?

    The cheapest flight price from Illinois to Seattle is $94. On average you can expect to pay $687. The most popular route, (Chicago O'Hare Intl - Seattle/Tacoma Intl), can usually be booked for $118.

  • Can I find deals for flights from Illinois to Seattle that include hotel bookings?

    Yes. In addition to deals on Illinois to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Illinois to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Illinois to Seattle.

  • Can I find deals for business class flights from Illinois to Seattle?

    Yes. Cheapflights offers flight deals from Illinois to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Illinois to Seattle?

    Currently, January is the cheapest month in which you can book a flight from Illinois to Seattle (average of $238). Flying from Illinois to Seattle in June is currently the most expensive (average of $388). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
SeaTac
Tukwila
Tacoma
Lakewood
Ocean Shores
Lynnwood
Edmonds
Leavenworth
Lacey
Renton
Olympia
Kent
Federal Way
Cle Elum
Puyallup
Chehalis
Kirkland
Issaquah
Aberdeen
Shoreline

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Top 8 airlines flying from Illinois to Seattle

Discover the top 8 airlines that operate flights from Illinois to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated septembre 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
Hawaiian AirlinesCheapest$90Average$250FlexibilityNo cancel feeOn-time85%
Spirit AirlinesCheapest$97Average$202FlexibilityNo cancel feeOn-time65%
DeltaCheapest$121Average$288FlexibilityNo cancel feeOn-timeN/A
FrontierCheapest$122Average$264FlexibilityNo cancel feeOn-time62%
Alaska AirlinesCheapest$168Average$451FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$170Average$448FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$176Average$450FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$194Average$417FlexibilityNo cancel feeOn-time63%

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