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$85+ Cheap flights from Seattle (SEA) to Illinois

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 12/17. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ORD
Nov 26 — Dec 31
Tue 11/26
Tue 12/3
1 adult, Economy
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Cheap flight deals from Seattle to Illinois

Discover tips and strategies to find the most affordable flight options for your journey from Seattle (SEA) to Illinois (USIL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated November 21, 2024.

Find flight deals from Seattle to Illinois

Cheapest flights from Seattle to Illinois
Explore the most affordable flight options available from Seattle to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on November 21, 2024.

This ezTravel 易遊網 deal was found by Cheapflights users on 11/19. 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 ezTravel 易遊網 is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/139:57 amSEA - ORD
1 stop7h 33mMultiple Airlines
Mon 12/166:32 amORD - SEA
Nonstop4h 48mMultiple Airlines
Deal found 11/19$175
This Mytrip deal was found by Cheapflights users on 11/20. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/139:57 amSEA - ORD
1 stop7h 33mFrontier
Mon 12/168:25 pmORD - SEA
1 stop23h 56mFrontier
Deal found 11/20$176
This Delta deal was found by Cheapflights users on 11/21. 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.
Sat 12/146:15 amSEA - ORD
Nonstop4h 02mDelta
Mon 12/162:10 pmORD - SEA
Nonstop4h 48mDelta
Deal found 11/21$178
This CheapOair deal was found by Cheapflights users on 11/20. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 12/81:40 pmSEA - MDW
1 stop20h 08mFrontier
Thu 12/1212:43 pmMDW - SEA
1 stop22h 14mFrontier
Deal found 11/20$178
This Alaska Airlines deal was found by Cheapflights users on 11/19. 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 12/145:51 pmSEA - ORD
Nonstop3h 56mAlaska Airlines
Mon 12/166:32 amORD - SEA
Nonstop4h 48mAlaska Airlines
Deal found 11/19$183
This Mytrip deal was found by Cheapflights users on 11/20. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/114:00 pmSEA - ORD
1 stop11h 30mSpirit Airlines
Tue 12/179:10 pmORD - SEA
1 stop18h 01mSpirit Airlines
Deal found 11/20$195
This United Airlines deal was found by Cheapflights users on 11/21. 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.
Thu 12/129:25 amSEA - ORD
1 stop8h 15mUnited Airlines
Mon 12/169:20 amORD - SEA
Nonstop4h 48mUnited Airlines
Deal found 11/21$202
This Delta deal was found by Cheapflights users on 11/20. 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.
Wed 12/411:05 pmSEA - STL
1 stop8h 31mDelta
Sat 12/147:20 amSTL - SEA
1 stop7h 15mDelta
Deal found 11/20$236
This eDestinos deal was found by Cheapflights users on 11/20. 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 eDestinos is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 12/44:00 pmSEA - MDW
1 stop17h 48mMultiple Airlines
Fri 12/64:27 pmMDW - SEA
3 stops42h 30mMultiple Airlines
Deal found 11/20$240
This American Airlines deal was found by Cheapflights users on 11/21. 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.
Mon 12/911:59 pmSEA - STL
1 stop6h 55mAmerican Airlines
Fri 12/132:29 pmSTL - SEA
1 stop7h 45mAmerican Airlines
Deal found 11/21$242
This Alaska Airlines deal was found by Cheapflights users on 11/21. 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.
Fri 12/136:06 pmSEA - STL
Nonstop3h 53mAlaska Airlines
Sat 12/147:00 amSTL - SEA
Nonstop4h 34mAlaska Airlines
Deal found 11/21$262
This American Airlines deal was found by Cheapflights users on 11/19. 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.
Thu 12/1212:15 amSEA - ORD
Nonstop4h 02mAmerican Airlines
Mon 12/169:55 amORD - SEA
Nonstop4h 48mAmerican Airlines
Deal found 11/19$277

Find flights from Seattle to Illinois within your budget

Customize your flight search to find flights from Seattle to Illinois 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 2,612,795 searches. Data last updated November 21, 2024.

Fly from

Any airport

Fly to

Any airport

Route

Depart

Return

Price

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Fri 12/13

9:57 am-7:30 pm

1 stop7h 33m

Chicago O'Hare Intl

Mon 12/16

6:32 am-9:20 am

Nonstop4h 48m

$175

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Fri 12/13

9:57 am-7:30 pm

1 stop7h 33m

Chicago O'Hare Intl

Mon 12/16

8:25 pm-6:21 pm

1 stop23h 56m

$176

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Wed 1/15

7:10 am-1:15 pm

Nonstop4h 05m

Chicago O'Hare Intl

Sun 1/19

7:00 am-9:58 am

Nonstop4h 58m

$178

SeattleChicago

SEA - MDW

SEAMDW

Seattle/Tacoma Intl

Sun 12/8

1:40 pm-11:48 am

1 stop20h 08m

Chicago Midway

Thu 12/12

12:43 pm-8:57 am

1 stop22h 14m

$178

SeattleChicago

SEA - MDW

SEAMDW

Seattle/Tacoma Intl

Wed 1/15

10:40 am-4:40 pm

Nonstop4h 00m

Chicago Midway

Fri 1/17

5:35 pm-8:10 pm

Nonstop4h 35m

$179

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Sat 12/14

5:51 pm-11:47 pm

Nonstop3h 56m

Chicago O'Hare Intl

Mon 12/16

6:32 am-9:20 am

Nonstop4h 48m

$183

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Tue 3/18

1:35 pm-7:40 pm

Nonstop4h 05m

Chicago O'Hare Intl

Tue 5/6

8:20 pm-10:58 pm

Nonstop4h 38m

$189

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Wed 12/11

4:00 pm-5:30 am

1 stop11h 30m

Chicago O'Hare Intl

Tue 12/17

9:10 pm-1:11 pm

1 stop18h 01m

$195

SeattleChicago

SEA - MDW

SEAMDW

Seattle/Tacoma Intl

Thu 1/9

12:13 pm-11:48 am

1 stop21h 35m

Chicago Midway

Mon 1/13

11:33 am-5:00 pm

3 stops31h 27m

$197

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Wed 12/4

11:05 pm-9:36 am

1 stop8h 31m

Lambert-St Louis

Sat 12/14

7:20 am-12:35 pm

1 stop7h 15m

$236

Flights are sorted by cheapest round-trip flights first.

Deals found on 11/20

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

Have a flexible travel schedule? Discover the best time to fly to Illinois from Seattle 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 Seattle to Illinois

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

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

Currently, September is the cheapest month in which you can book a flight from Seattle to Illinois (average of $232). Flying from Seattle to Illinois in June is currently the most expensive (average of $308). 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 SEA to IL?

Find hourly flight availability from Seattle to Illinois. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated November 21, 2024.

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

Weekly flight availability from Seattle to Illinois

Explore weekly flight availability from Seattle to Illinois. 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 November 21, 2024.

The most flights from SEA to USIL are scheduled on a Thursday (46 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (12 on average).

Rainfall in Illinois by month

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

In terms of precipitation, rainfall in Illinois ranges from 1.7 - 4.9 inches per month. August is typically the wettest month, when rainfall can reach 4.9 in. January is typically the driest time to visit Illinois when rainfall is around 1.7 in.

Temperature in Illinois by month

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

If weather is an important factor for your trip to Illinois, 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 73.4 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 23.0 F).

Reviews of airlines servicing Illinois

Get insights into the airlines that provide service to Illinois. 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 Illinois. Reviews last updated November 21, 2024.
Read reviews from past customers who have flown Frontier, Delta and Alaska Airlines from Seattle to Illinois. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.1
Very good
5,005 reviews

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Crew

8.7

Overall

8.1

Food

7.2

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

Southwest
8.1
Very good
5,005 reviews
Southwest
8.1
Very good
5,005 reviews

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Crew

8.7

Overall

8.1

Food

7.2

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

Alaska Airlines
8.0
Very good
9,464 reviews
Southwest
8.1
Very good
5,005 reviews

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Crew

8.7

Overall

8.1

Food

7.2

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

Delta
8.0
Very good
8,755 reviews
Southwest
8.1
Very good
5,005 reviews

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Crew

8.7

Overall

8.1

Food

7.2

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

United Airlines
7.4
Good
9,172 reviews
Southwest
8.1
Very good
5,005 reviews

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Crew

8.7

Overall

8.1

Food

7.2

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

WestJet
7.3
Good
2,811 reviews
Southwest
8.1
Very good
5,005 reviews

Entertainment

7.7

Boarding

8.2

Comfort

8.1

Crew

8.7

Overall

8.1

Food

7.2

Reviews

1 / 10

Great service throughout our flight. Easy boarding with early bird check in

Related info for your journey

Find useful and relevant information for your journey from Seattle to Illinois. 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 from for flights from Seattle to Illinois?

    Most people fly from Seattle/Tacoma Intl (SEA) if they book a flight from Seattle to Illinois. Seattle/Tacoma Intl is conveniently located just 11.4 mi from Seattle’s city center.

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

    The cheapest airlines for a one-way flight from Seattle to Illinois are Frontier ($85), Southwest ($85), and Alaska Airlines ($90).

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

    The most popular flight routes from Seattle to Illinois are Seattle/Tacoma Intl - Chicago O'Hare Intl, Seattle/Tacoma Intl - Chicago Midway and Seattle/Tacoma Intl - Lambert-St Louis.

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

    No one likes to see their flight delayed. When booking a flight from Seattle to Illinois consider choosing Avianca (100%), KLM (98%) or WestJet (98%) as they are the most reliable in getting you off to your destination on time.

  • What are the cheapest flights from Seattle to Illinois?

    On average you can expect to pay $777 for a flight from Seattle to Illinois. The cheapest flight overall is $93 while the most popular route, (Seattle/Tacoma Intl - Chicago O'Hare Intl) is currently priced at $153.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Seattle to Illinois 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 Seattle to Illinois?

    Currently, September is the cheapest month in which you can book a flight from Seattle to Illinois (average of $232). Flying from Seattle to Illinois in June is currently the most expensive (average of $308). 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.

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Alternative routes for Seattle to Illinois

See prices for flight routes from nearby airports that may be better suited for you.
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Top 7 airlines flying from Seattle to Illinois

Discover the top 7 airlines that operate flights from Seattle to Illinois. 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 2,612,795 searches. Data last updated November 21, 2024.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$100Average$439FlexibilityNo cancel feeOn-timeN/A
Spirit AirlinesCheapest$116Average$245FlexibilityNo cancel feeOn-time65%
Alaska AirlinesCheapest$127Average$525FlexibilityNo cancel feeOn-time75%
FrontierCheapest$131Average$267FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$136Average$516FlexibilityNo cancel feeOn-time71%
United AirlinesCheapest$154Average$561FlexibilityNo cancel feeOn-time69%
SouthwestCheapest$200Average$401FlexibilityNo cancel feeOn-time63%
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