SEA

$63 Find Cheap Flights from Illinois to Seattle

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight to Seattle departing on 1/7. 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
1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$176
Overall average: $341
American Airlines
Thu 1/8Thu 1/15
STL - SEA • 1 stop
Cheapest non-stop
$177
Typical prices: $188-$199
Southwest
Thu 1/8Sun 1/11
MDW - SEA • Non-stop
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Flight Deals
Useful Info
Flight Deals

Cheap Flights from Illinois to Seattle

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Illinois to Seattle that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Illinois to Seattle

Thu, Jan 8 - Thu, Jan 15
American Airlines Logo
2:38 pm - 8:57 pm
STL
-
SEA
8h 19m1 stop
American Airlines Logo
7:35 am - 4:14 pm
SEA
-
STL
6h 39m1 stop
$176American Airlines
Thu, Jan 8 - Mon, Jan 12
Southwest Logo
10:35 am - 1:15 pm
MDW
-
SEA
4h 40mnonstop
Southwest Logo
6:45 am - 12:40 pm
SEA
-
MDW
3h 55mnonstop
$177Southwest
Thu, Jan 8 - Mon, Jan 12
United Airlines Logo
1:20 pm - 4:01 pm
ORD
-
SEA
4h 41mnonstop
United Airlines Logo
2:10 pm - 8:17 pm
SEA
-
ORD
4h 07mnonstop
$177United Airlines
Wed, Mar 11 - Mon, Mar 16
Delta Logo
6:04 pm - 12:01 am
STL
-
SEA
7h 57m1 stop
Delta Logo
11:59 pm - 8:50 am
SEA
-
STL
6h 51m1 stop
$177Delta
Wed, Jan 7 - Fri, Jan 30
Frontier Logo
7:43 pm - 11:21 am
STL
-
SEA
17h 38m1 stop
Frontier Logo
10:51 am - 2:46 pm
SEA
-
STL
25h 55m2 stops
$179Frontier
Sun, Jan 11 - Sun, Jan 25
Frontier Logo
12:50 pm - 4:29 pm
MDW
-
SEA
29h 39m1 stop
Frontier Logo
12:34 pm - 3:49 pm
SEA
-
MDW
25h 15m2 stops
$180Frontier
Tue, Jan 13 - Thu, Jan 15
Multiple Airlines Logo
3:35 pm - 6:22 pm
ORD
-
SEA
4h 47mnonstop
Multiple Airlines Logo
12:19 pm - 9:24 pm
SEA
-
ORD
7h 05m1 stop
$180Multiple Airlines
Thu, Jan 8 - Tue, Jan 13
United Airlines Logo
7:54 pm - 10:43 pm
ORD
-
SEA
4h 49mnonstop
United Airlines Logo
12:35 pm - 11:14 pm
SEA
-
ORD
8h 39m1 stop
$183United Airlines
Thu, Jan 15 - Tue, Jan 20
Multiple Airlines Logo
2:30 pm - 11:09 am
ORD
-
SEA
22h 39m1 stop
Multiple Airlines Logo
5:50 pm - 11:50 pm
SEA
-
ORD
4h 00mnonstop
$185Multiple Airlines
Thu, Jan 15 - Thu, Jan 22
Delta Logo
6:10 am - 10:55 am
STL
-
SEA
6h 45m1 stop
Delta Logo
5:00 am - 1:48 pm
SEA
-
STL
6h 48m1 stop
$198Delta
Useful Info

Good to know

Low seasonJanuary
Cheapest flight$63
Best time to beat the crowds with an average 15% drop in price.
Most popular time to fly with an average 15% increase in price.
Flight from St. Louis to Seattle

Flights from Illinois to Seattle: the best tips from KAYAK users

Insights shared by verified travelers who flew the route from Illinois to Seattle 
Learn how KAYAK collects reviews and tips from users.
PaulFlew with Alaska Airlines
ORD
-
SEA
Apr 2024
The flight is long, at over four hours. I would try to get a window or aisle seat to be more comfortable. I would check with other airlines that allow you to choose your seat even if you are in the economy section. I would bring your own food on the plane as the service was sometimes sketchy.
Verified travelerFlew with Alaska Airlines
ORD
-
SEA
Apr 2024
If you miss your flight ask any alaska agent to how and where to rebook the flight.

FAQs for booking flights from Illinois to Seattle

  • How does KAYAK find such low prices on flights from Illinois to Seattle?

    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 Illinois to Seattle.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from Illinois to Seattle?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Seattle from Illinois 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 Illinois to Seattle?

    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 Seattle with an airline and back to Illinois with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from Illinois to Seattle?

    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 Seattle from Illinois up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Lynnwood
Centralia
Fife
Westport
Lakewood
Mukilteo
Lacey
Poulsbo
Edmonds
Aberdeen
Woodinville
Shoreline
DuPont
Monroe
Castle Rock
Edgewood

Everything you need to know for your flight to Seattle

Information on the airport you'll fly into in Seattle

Seattle (SEA)