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$55+ 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 4/23. Fares are subject to change and may not be available on all flights or dates of travel.
ORD — SEA
Feb 25 — Mar 41
Tue 2/25
Tue 3/4
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 February 20, 2025.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$173
(Booking.com)

One-way from

$55
(Frontier)

Popular in

July

Cheapest in

September

Average price

$229

Good round-trip deal

$253 or less

Good one-way deal

$93 or less
Provider with most accurate pricing for Chicago (CHI)-Seattle/Tacoma Intl flight deals.
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Provider most trusted by Cheapflights users for Chicago (CHI)-Seattle/Tacoma Intl flights.
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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. 18% potential increase in price ($64 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($9 potential savings vs. average RT price).
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Average for round-trip flights in February 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 February 20, 2025.

This Booking.com deal was found by Cheapflights users on 2/19. 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.
Mon 3/106:30 amORD - SEA
1 stop7h 32mMultiple Airlines
Sun 3/1612:41 pmSEA - ORD
1 stop16h 01mMultiple Airlines
Deal found 2/19$173
This CheapOair deal was found by Cheapflights users on 2/19. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/96:40 amMDW - SEA
1 stop7h 22mFrontier
Sat 3/1512:03 pmSEA - MDW
1 stop15h 27mFrontier
Deal found 2/19$175
This FlightHub deal was found by Cheapflights users on 2/20. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 3/122:42 pmORD - SEA
1 stop23h 04mSpirit Airlines
Sun 3/1612:41 pmSEA - ORD
1 stop16h 01mSpirit Airlines
Deal found 2/20$176
This Delta deal was found by Cheapflights users on 2/19. 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.
Thu 3/132:55 pmMDW - SEA
1 stop9h 01mDelta
Tue 3/1810:55 pmSEA - MDW
1 stop7h 50mDelta
Deal found 2/19$177
This Delta deal was found by Cheapflights users on 2/20. 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.
Tue 3/187:15 pmORD - SEA
1 stop6h 54mDelta
Mon 3/2412:49 amSEA - ORD
1 stop5h 55mDelta
Deal found 2/20$177
This Frontier deal was found by Cheapflights users on 2/20. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 3/96:45 amORD - SEA
1 stop7h 17mFrontier
Sun 3/92:02 pmSEA - ORD
1 stop8h 21mFrontier
Deal found 2/20$185
This Alaska Airlines deal was found by Cheapflights users on 2/19. 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.
Sat 4/58:00 amORD - SEA
Nonstop4h 39mAlaska Airlines
Sat 4/126:02 pmSEA - ORD
Nonstop3h 57mAlaska Airlines
Deal found 2/19$189
This Southwest deal was found by Cheapflights users on 2/20. 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.
Thu 3/274:55 pmMDW - SEA
Nonstop4h 35mSouthwest
Mon 3/317:00 pmSEA - MDW
1 stop13h 35mSouthwest
Deal found 2/20$203
This American Airlines deal was found by Cheapflights users on 2/19. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/45:00 amORD - SEA
1 stop8h 00mAmerican Airlines
Sun 4/611:59 pmSEA - ORD
Nonstop4h 05mAmerican Airlines
Deal found 2/19$203
This United Airlines deal was found by Cheapflights users on 2/19. 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.
Fri 3/78:48 amORD - SEA
1 stop9h 06mUnited Airlines
Wed 3/1211:59 pmSEA - ORD
Nonstop3h 54mUnited Airlines
Deal found 2/19$205
This Delta deal was found by Cheapflights users on 2/19. 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.
Mon 3/105:35 pmSTL - SEA
1 stop7h 57mDelta
Fri 3/145:30 amSEA - STL
1 stop5h 53mDelta
Deal found 2/19$229
This American Airlines deal was found by Cheapflights users on 2/19. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/23:33 pmPIA - SEA
1 stop9h 36mAmerican Airlines
Wed 4/91:35 pmSEA - PIA
1 stop6h 28mAmerican Airlines
Deal found 2/19$229

Find flights from Illinois to Seattle within your budget

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 February 20, 2025.

Fly from

Illinois

Fly to

Seattle

Route

Depart

Return

Price

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Fri 4/4

7:00 am-9:36 am

Nonstop4h 36m

Seattle/Tacoma Intl

Sat 4/12

6:02 pm-11:59 pm

Nonstop3h 57m

$173

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Wed 3/19

12:30 pm-7:09 pm

1 stop8h 39m

Seattle/Tacoma Intl

Wed 3/26

9:48 am-1:38 am

2 stops13h 50m

$174

ChicagoSeattle

MDW - SEA

MDWSEA

Chicago Midway

Sun 3/9

6:40 am-12:02 pm

1 stop7h 22m

Seattle/Tacoma Intl

Sat 3/15

12:03 pm-5:30 am

1 stop15h 27m

$175

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Sat 3/8

6:54 pm-8:30 am

1 stop15h 36m

Seattle/Tacoma Intl

Sun 3/16

12:41 pm-6:42 am

1 stop16h 01m

$175

ChicagoSeattle

MDW - SEA

MDWSEA

Chicago Midway

Thu 3/13

2:55 pm-9:56 pm

1 stop9h 01m

Seattle/Tacoma Intl

Tue 3/18

10:55 pm-8:45 am

1 stop7h 50m

$177

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Tue 3/18

7:15 pm-12:09 am

1 stop6h 54m

Seattle/Tacoma Intl

Fri 3/21

10:00 pm-9:18 am

1 stop9h 18m

$177

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Wed 4/2

4:19 pm-7:01 pm

Nonstop4h 42m

Seattle/Tacoma Intl

Mon 4/7

11:45 pm-5:46 am

Nonstop4h 01m

$178

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Sun 3/9

6:45 am-12:02 pm

1 stop7h 17m

Seattle/Tacoma Intl

Thu 3/13

11:38 am-5:10 am

1 stop15h 32m

$180

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Sat 3/8

5:56 pm-8:37 pm

Nonstop4h 41m

Seattle/Tacoma Intl

Sun 3/16

11:59 pm-5:53 am

Nonstop3h 54m

$193

ChicagoSeattle

MDW - SEA

MDWSEA

Chicago Midway

Thu 3/27

4:55 pm-7:30 pm

Nonstop4h 35m

Seattle/Tacoma Intl

Mon 3/31

7:00 pm-10:35 am

1 stop13h 35m

$203

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/20

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.

Travel insights for flights from Illinois to Seattle

Get recent, data-driven insights about flights from Illinois to Seattle including ideal travel times, pricing trends, and more.

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 July is currently the most expensive (average of $411). 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 February 20, 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 February 20, 2025.

The most flights from USIL to SEA are scheduled on a Thursday (40 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (13 on average).

Rainfall in Seattle by month

Plan your trip to Seattle by taking into account the average rainfall totals by month.

In terms of precipitation, rainfall in Seattle ranges from 0.7 - 6.6 inches per month. November is typically the wettest month, when rainfall can reach 6.6 in. July is typically the driest time to visit Seattle when rainfall is around 0.7 in.

Temperature in Seattle by month

Plan your trip to Seattle by taking into account the average temperature totals by month.

If weather is an important factor for your trip to Seattle, use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 66.2 F. Travelers looking to avoid the cold should look outside of December, when temperatures are typically at their lowest (around 41.0 F).

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated February 20, 2025.
See what other customers who have flown with Southwest, Alaska Airlines and Delta from Illinois to Seattle have to say. Reviews also offer insight into each airline's entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Crew

8.7

Food

7.1

Comfort

8.1

Boarding

8.2

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Southwest
8.1
Very good
4,411 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Crew

8.7

Food

7.1

Comfort

8.1

Boarding

8.2

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Alaska Airlines
8.0
Very good
9,692 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Crew

8.7

Food

7.1

Comfort

8.1

Boarding

8.2

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Delta
8.0
Very good
8,220 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Crew

8.7

Food

7.1

Comfort

8.1

Boarding

8.2

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

Hawaiian Airlines
7.9
Good
2,317 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Crew

8.7

Food

7.1

Comfort

8.1

Boarding

8.2

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

United Airlines
7.4
Good
8,766 reviews
Southwest
8.1
Very good
4,411 reviews

Entertainment

7.6

Crew

8.7

Food

7.1

Comfort

8.1

Boarding

8.2

Overall

8.1

Reviews

1 / 20

2.0
Mediocre

Anonymous,Feb 2025

MCO - STL

Cancelled at last minute, SWA unable to assist in formulating alternate plans. Wound up renting a car and driving 13 hours to beat bad weather forecast at home. Not SWA’s fault that there was significant bad weather across the country.

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.

  • 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 Frontier ($55), Spirit Airlines ($88), and Delta ($89).

  • 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: Air France (81%), Royal Jordanian (81%), Turkish Airlines (75%).

  • What are the cheapest flights from Illinois to Seattle?

    The cheapest flight price from Illinois to Seattle is $89. On average you can expect to pay $655. The most popular route, (Chicago O'Hare Intl - Seattle/Tacoma Intl), can usually be booked for $133.

  • 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 July is currently the most expensive (average of $411). 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 Illinois?

Book flights to Illinois if you plan to visit one of these locations
SeaTac
Tukwila
Renton
Tacoma
Lacey
Ocean Shores
Leavenworth
Olympia
Federal Way
Centralia
Marysville
Cle Elum
Mukilteo
Aberdeen
Lakewood
Issaquah
Shoreline
Lynnwood
Shelton
Silverdale

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Alternative routes for Illinois to Seattle

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Top 7 airlines flying from Illinois to Seattle

Discover the top 7 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 February 20, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$118Average$223FlexibilityNo cancel feeOn-time62%
Spirit AirlinesCheapest$124Average$240FlexibilityNo cancel feeOn-time65%
Alaska AirlinesCheapest$127Average$521FlexibilityNo cancel feeOn-time75%
DeltaCheapest$128Average$399FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$149Average$529FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$159Average$472FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$188Average$348FlexibilityNo cancel feeOn-time63%
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