Cheap flights from Seattle (SEA) to Illinois (IL)

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How to find the cheapest flight from
Seattle (SEA) to Illinois

All the information you need to plan the best SEA to ORD flight in 2021: compare Seattle to Illinois flight prices with the expected peak season, weather and rainfall in Illinois.
What is the cheapest month to fly from Seattle to Illinois?

Flights from Seattle to Illinois lean towards being more expensive in December. Prices are generally better when you fly from Seattle to Illinois in August, with the cheapest ticket starting at $78.

When is the cheapest time to fly from Seattle to Illinois (SEA - IL)?

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.

How far in advance should I book a flight from Seattle to Illinois?

Users have found that booking a flight from Seattle to Illinois at least 57 days early can save you up to 13% on average compared to booking a flight this week. If booking 57 days before your flight isn’t an option for you, users have found flights from Seattle to Illinois for as little as $226 when booking for a departure date within the next two weeks. You can also check prices now. Some users have found airline tickets as low as $247 for flights departing within the next 3 days.

Cheap flights from Seattle to Illinois in November, December 2021

The best prices found for SEA to Illinois flights for November, December
13 Dec - 5 Jan
$136pp
SEA
Seattle/Tacoma Intl
Frontier
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
Frontier
 
1 STOP
SEA
Seattle/Tacoma Intl
14 Dec - 5 Jan
$159pp
SEA
Seattle/Tacoma Intl
Multiple Airlines
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
Frontier
 
1 STOP
SEA
Seattle/Tacoma Intl
10 Dec - 14 Dec
$165pp
SEA
Seattle/Tacoma Intl
Multiple Airlines
 
1 STOP
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Alaska Airlines
Non-Stop
SEA
Seattle/Tacoma Intl

Seattle/Tacoma Intl to Illinois 2022 flight deals

Cheap flights to Illinois from Seattle found for next year
13 Dec - 5 Jan
$136pp
SEA
Seattle/Tacoma Intl
Frontier
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
Frontier
 
1 STOP
SEA
Seattle/Tacoma Intl
14 Dec - 5 Jan
$159pp
SEA
Seattle/Tacoma Intl
Multiple Airlines
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
Frontier
 
1 STOP
SEA
Seattle/Tacoma Intl
10 Dec - 14 Dec
$165pp
SEA
Seattle/Tacoma Intl
Multiple Airlines
 
1 STOP
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Alaska Airlines
Non-Stop
SEA
Seattle/Tacoma Intl

Non-stop flights to Illinois from Seattle

Save time with Seattle to Illinois direct flight deals
1 Feb - 8 Feb
$162pp
SEA
Seattle/Tacoma Intl
Alaska Airlines
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Alaska Airlines
Non-Stop
SEA
Seattle/Tacoma Intl
29 Jan - 29 Jan
$172pp
SEA
Seattle/Tacoma Intl
Alaska Airlines
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Alaska Airlines
Non-Stop
SEA
Seattle/Tacoma Intl
5 Jan - 11 Jan
$176pp
SEA
Seattle/Tacoma Intl
Multiple Airlines
Non-Stop
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
United Airlines
Non-Stop
SEA
Seattle/Tacoma Intl

Last minute flights from Seattle to Illinois

Late deals on round-trip flights to Illinois from Seattle, departing today and this week
6 Dec - 10 Dec
$169pp
SEA
Seattle/Tacoma Intl
Multiple Airlines
 
1 STOP
STL
Lambert-St Louis
STL
Lambert-St Louis
Multiple Airlines
 
1 STOP
SEA
Seattle/Tacoma Intl
6 Dec - 11 Dec
$169pp
SEA
Seattle/Tacoma Intl
Multiple Airlines
 
1 STOP
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
Delta
Non-Stop
SEA
Seattle/Tacoma Intl
6 Dec - 11 Dec
$178pp
SEA
Seattle/Tacoma Intl
Multiple Airlines
 
1 STOP
ORD
Chicago O'Hare Intl
ORD
Chicago O'Hare Intl
United Airlines
 
1 STOP
SEA
Seattle/Tacoma Intl

One-way flights to Illinois from Seattle

The cheapest one-way flights from Seattle to Illinois
7:59 pm - 12:50 pm
Frontier
1 Stop
14h 51m
SEA - STL
Frontier
$83
Kiwi.com
2:50 pm - 1:54 pm
Spirit Airlines
1 Stop
21h 04m
SEA - STL
Spirit Airlines
$86
FareScan
7:59 pm - 6:30 pm
Multiple Airlines
2 Stops
20h 31m
SEA - ORD
Multiple Airlines
$87
Kiwi.com

Related info for your journey

Useful info, stats and facts about <span class="emphasized">Seattle</span> to <span class="emphasized">Illinois</span> flights.

Flight FAQs

From Seattle to Illinois

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.

Which airlines flying from Seattle/Tacoma Intl to Illinois have flexible cancellations due to COVID-19?

Some of our airline partners flying from Seattle/Tacoma Intl to Illinois have new flexible policies in place due to COVID-19. Alaska Airlines, Delta, and United Airlines are some of the carriers where you may find flexible cancellation policies. You can use our site to filter for airlines like Alaska Airlines with this kind of flexibility.

Can I find flights from Seattle to Illinois for under $200 on Cheapflights?

Yes, there are multiple flights from Seattle to Illinois for under $200. The cheapest flight booked recently is on Multiple Airlines for just $117, but on average you can expect to pay $144.

Are there nonstop flights from Seattle to Illinois for under $200 on Cheapflights?

Cheapflights has at least 20 direct flights from Seattle to Illinois under $200. A good price for a nonstop flight from Seattle to Illinois is less than $191.

Are there last-minute flights available from Seattle to Illinois for under $200?

There are currently 20+ open flights from Seattle to Illinois within the next 7 days for less than $200.

What days are nonstop flights available from Seattle to Illinois?

Days when nonstop flights are available for this flight are: Monday, Tuesday, Wednesday, Thursday, Friday, Saturday.

How many flights depart from Seattle to Illinois on average per day?

Per day, 44 flights depart from Seattle to Illinois on average.
Early Morning (Midnight to 6am) - 20% of flight departures
Morning (6am - Noon) - 30% of flight departures
Afternoon (Noon - 6pm) - 36% of flight departures
Evening (6pm - Midnight) - 14% of flight departures

How long is the flight from Seattle to Illinois?

Airlines like Frontier, Spirit Airlines, and Alaska Airlines fly from Seattle to Illinois in about 3h 58m. The time it takes to get you to your destination can typically vary by up to 4h 11m. The distance between Seattle and Illinois is about 1725 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 Seattle to Illinois one-way?

The cheapest airlines for a one-way flight from Seattle to Illinois are Frontier ($54), Spirit Airlines ($66), and Alaska Airlines ($68).

What are the most popular airlines that fly from Seattle to Illinois?

The most popular airlines flying from Seattle to Illinois are Major Airline, American Airlines and Alaska Airlines. Something to consider prior to booking your flight.

What are the cheapest flights from Seattle to Illinois?

On average you can expect to pay $354 for a flight from Seattle to Illinois. The cheapest flight overall is $43 while the most popular route, (Seattle/Tacoma Intl - Chicago O'Hare Intl) is currently priced at $169.

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 Air France (100%), Iberia (96%) or Royal Jordanian (92%) as they are the most reliable in getting you off to your destination on time.

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.

COVID Restrictions

View COVID Travel Restrictions for Illinois (IL)

Do I need a COVID test to fly to Illinois from Seattle?

Information is based on travel restrictions for travel to Illinois within the United States

Most visitors from Seattle/Tacoma Intl need to provide a negative COVID-19 test result and/or quarantine to enter Illinois.

COVID-19 testing requirements
Visitors from Seattle/Tacoma Intl must present a negative RT-PCR (NAAT) or Antigen (quick-test) test taken 72 hours before departing to Illinois.

Quarantine requirements
Visitors from Seattle/Tacoma Intl are not required to quarantine after entering Illinois.

Do I need a test to fly back to Seattle from Illinois?

Returning to Seattle/Tacoma Intl from Illinois

COVID-19 testing requirements
Visitors from Illinois must present a negative RT-PCR (NAAT) or Antigen (quick-test) test taken 72 hours before departing to Seattle/Tacoma Intl.

Quarantine requirements
Visitors from Illinois are not required to quarantine after entering Seattle/Tacoma Intl.

Hide COVID Travel Restrictions for Illinois (IL)

Destination points for flights from Seattle to Illinois

Select to see more specific information for flights from Seattle to all places in Illinois.

Destination information for Illinois

Things to know before you go - useful duration and weather info for your trip from Seattle to Illinois.
Flight duration from SEA to Illinois
4h 19m

Airports servicing Seattle

Airports servicing

Bloomington (BMI)
Champaign (CMI)
Decatur (DEC)
Moline (MLI)
Marion (MWA)

Top 7 airlines flying from Seattle/Tacoma Intl to Illinois

The chart below displays the airlines Cheapflights users traveling from Seattle to Illinois choose most often. Cheapest and average prices are based on aggregated data from the past 12 months.
Airline Cheapest Average Flexibility On-time COVID-19 safety
Spirit Airlines
$84 $211 No cancel fee 65%
Delta
$86 $358 No cancel fee N/A
United Airlines
$95 $388 No cancel fee 69%
American Airlines
$103 $404 No cancel fee 71%
Frontier
$108 $270 No cancel fee 62%
Alaska Airlines
$110 $312 No cancel fee 75%
Southwest
$355 $610 No cancel fee 63%
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