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$145 Find Cheap Flights from Illinois to Seattle - Compare and Save

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1 adult, Economy, 0 bags

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Flight Deals

Cheap Flights from Illinois to Seattle

 
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from Illinois to Seattle

Wed, Oct 21 - Fri, Oct 23
Frontier Logo
6:30 am - 3:12 pmORD  Chicago O'Hare Intl-SEA Seattle/Tacoma Intl
10h 42m1 stop Denver Intl
Frontier Logo
8:00 pm - 6:34 amSEA  Seattle/Tacoma Intl-ORD Chicago O'Hare Intl
8h 34m1 stop Los Angeles
$273Frontier
Wed, Oct 14 - Thu, Oct 15
Frontier Logo
8:01 pm - 6:45 pmORD  Chicago O'Hare Intl-SEA Seattle/Tacoma Intl
24h 44m1 stop Los Angeles
Frontier Logo
9:16 pm - 5:16 amSEA  Seattle/Tacoma Intl-ORD Chicago O'Hare Intl
30h 00m1 stop Las Vegas Harry Reid Intl
$276Frontier
Sat, Nov 7 - Sat, Nov 14
Multiple Airlines Logo
9:30 am - 12:14 pmORD  Chicago O'Hare Intl-SEA Seattle/Tacoma Intl
4h 44mnonstop
Multiple Airlines Logo
4:27 pm - 12:21 amSEA  Seattle/Tacoma Intl-ORD Chicago O'Hare Intl
5h 54m1 stop Denver Intl
$277Multiple Airlines
Wed, Oct 21 - Sat, Oct 31
Multiple Airlines Logo
3:49 pm - 6:28 pmORD  Chicago O'Hare Intl-SEA Seattle/Tacoma Intl
4h 39mnonstop
Multiple Airlines Logo
4:27 pm - 12:21 amSEA  Seattle/Tacoma Intl-ORD Chicago O'Hare Intl
5h 54m1 stop Denver Intl
$278Multiple Airlines
Thu, Oct 15 - Wed, Oct 21
Alaska Airlines Logo
6:07 am - 12:23 pmORD  Chicago O'Hare Intl-SEA Seattle/Tacoma Intl
8h 16m1 stop San Francisco
Alaska Airlines Logo
10:33 am - 4:50 pmSEA  Seattle/Tacoma Intl-ORD Chicago O'Hare Intl
4h 17mnonstop
$280Alaska Airlines
Thu, Nov 5 - Thu, Nov 12
Alaska Airlines Logo
7:00 am - 9:50 amORD  Chicago O'Hare Intl-SEA Seattle/Tacoma Intl
4h 50mnonstop
Alaska Airlines Logo
5:51 pm - 11:59 pmSEA  Seattle/Tacoma Intl-ORD Chicago O'Hare Intl
4h 08mnonstop
$287Alaska Airlines
Sat, Oct 24 - Tue, Oct 27
American Airlines Logo
4:42 pm - 12:10 amPIA  Greater Peoria-SEA Seattle/Tacoma Intl
9h 28m1 stop Dallas/Fort Worth
American Airlines Logo
6:12 am - 4:59 pmSEA  Seattle/Tacoma Intl-PIA Greater Peoria
8h 47m1 stop Chicago O'Hare Intl
$288American Airlines
Wed, Jan 6 - Wed, Jan 20
American Airlines Logo
4:18 pm - 10:35 pmPIA  Greater Peoria-SEA Seattle/Tacoma Intl
8h 17m1 stop Dallas/Fort Worth
American Airlines Logo
2:39 pm - 11:56 pmSEA  Seattle/Tacoma Intl-PIA Greater Peoria
7h 17m1 stop Chicago O'Hare Intl
$301American Airlines
Wed, Jan 6 - Wed, Jan 20
United Airlines Logo
5:41 pm - 10:39 pmPIA  Greater Peoria-SEA Seattle/Tacoma Intl
6h 58m1 stop Chicago O'Hare Intl
United Airlines Logo
6:29 am - 6:59 pmSEA  Seattle/Tacoma Intl-PIA Greater Peoria
10h 30m2 stops Los Angeles Chicago O'Hare Intl
$306United Airlines
Sat, Oct 24 - Tue, Oct 27
United Airlines Logo
10:43 am - 3:52 pmPIA  Greater Peoria-SEA Seattle/Tacoma Intl
7h 09m1 stop Chicago O'Hare Intl
United Airlines Logo
9:05 am - 11:13 pmSEA  Seattle/Tacoma Intl-PIA Greater Peoria
12h 08m2 stops San Francisco Chicago O'Hare Intl
$306United Airlines
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Good to know

Low season

January

Cheapest flight

$145
Best time to beat the crowds with an average 25% drop in price.
Most popular time to fly with an average 24% increase in price.
Flight from Chicago O'Hare Airport 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 
MatthewFlew with United Airlines-Jul 2026
When in Seattle, take public trans at least to downtown as Uber/Lyft is expensive
PaulFlew with Alaska Airlines-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-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
Lakewood
Westport
Lacey
Mukilteo
Woodinville
Poulsbo
Edmonds
Aberdeen
DuPont
Shoreline
Monroe
Castle Rock
Edgewood

More options for your flight to Seattle