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Cheap flights from Illinois to Seattle from $66

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Illinois to Seattle departing on 4/25. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
0 bags

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Find the cheapest flights from Illinois to Seattle

Cheap round-trip flights

Enter your travel dates to find the best prices.
American Airlines Logo
5:21 pm - 12:36 am
STL
-
SEA
9h 15m
1 stop
American Airlines Logo
7:00 am - 4:41 pm
SEA
-
STL
7h 41m
1 stop
$177American Airlines
Tue, Apr 21 - Sat, Apr 25
Southwest Logo
6:15 am - 5:55 pm
MDW
-
SEA
13h 40m
1 stop
Southwest Logo
11:55 pm - 5:55 am
SEA
-
MDW
4h 00mnonstop
$179Southwest
Sat, May 2 - Sat, May 9
Frontier Logo
11:07 am - 9:27 am
ORD
-
SEA
24h 20m
2 stops
Frontier Logo
10:42 am - 5:50 am
SEA
-
ORD
17h 08m
1 stop
$179Frontier
Tue, Apr 28 - Wed, May 6
Multiple Airlines Logo
6:20 am - 5:42 pm
ORD
-
SEA
13h 22m
1 stop
Multiple Airlines Logo
10:25 pm - 5:50 am
SEA
-
ORD
29h 25m
1 stop
$180Multiple Airlines
Thu, Apr 30 - Sun, May 3
Frontier Logo
8:06 pm - 9:27 am
STL
-
SEA
15h 21m
1 stop
Frontier Logo
7:12 pm - 7:21 pm
SEA
-
STL
22h 09m
1 stop
$181Frontier
Fri, Apr 24 - Sat, May 2
Multiple Airlines Logo
5:15 am - 8:51 pm
ORD
-
SEA
17h 36m
2 stops
Multiple Airlines Logo
9:19 pm - 6:47 am
SEA
-
ORD
31h 28m
1 stop
$181Multiple Airlines
Fri, May 1 - Mon, May 4
Delta Logo
12:46 pm - 3:20 pm
ORD
-
SEA
4h 34mnonstop
Delta Logo
6:00 am - 4:51 pm
SEA
-
ORD
8h 51m
1 stop
$182Delta
Wed, May 6 - Sun, May 10
Delta Logo
5:35 pm - 11:54 pm
STL
-
SEA
8h 19m
1 stop
Delta Logo
1:25 pm - 12:30 am
SEA
-
STL
9h 05m
1 stop
$185Delta
Fri, May 1 - Mon, May 11
United Airlines Logo
5:33 pm - 10:39 pm
PIA
-
SEA
7h 06m
1 stop
United Airlines Logo
11:52 pm - 10:10 am
SEA
-
PIA
8h 18m
1 stop
$309United Airlines
Wed, Jul 1 - Wed, Jul 8
United Airlines Logo
7:34 pm - 12:34 am
MLI
-
SEA
7h 00m
1 stop
United Airlines Logo
8:38 am - 9:02 pm
SEA
-
MLI
10h 24m
2 stops
$314United Airlines
Thu, Apr 23 - Sat, May 2

Delta flights from Illinois to Seattle

Our best Delta deals on Illinois to Seattle flight tickets
Delta
May 6
ORD12:46 pmChicago O'Hare Intl
4h 34m
SEA3:20 pmSeattle/Tacoma Intl
May 10
SEA6:00 amSeattle/Tacoma Intl
8h 51m
1 stop
ORD4:51 pmChicago O'Hare Intl
$182
Delta
May 1
STL5:35 pmLambert-St Louis
8h 19m
1 stop
SEA11:54 pmSeattle/Tacoma Intl
May 11
SEA1:25 pmSeattle/Tacoma Intl
9h 05m
1 stop
STL12:30 amLambert-St Louis
$185
Delta
Apr 4
STL6:29 amLambert-St Louis
6h 26m
1 stop
SEA10:55 amSeattle/Tacoma Intl
Apr 8
SEA5:30 amSeattle/Tacoma Intl
5h 47m
1 stop
STL1:17 pmLambert-St Louis
$187

Southwest flights from Illinois to Seattle

Our best Southwest deals on Illinois to Seattle flight tickets
Southwest
May 2
MDW6:15 amChicago Midway
13h 40m
1 stop
SEA5:55 pmSeattle/Tacoma Intl
May 9
SEA11:55 pmSeattle/Tacoma Intl
4h 00m
MDW5:55 amChicago Midway
$179
Southwest
Mar 21
MDW9:40 pmChicago Midway
4h 35m
SEA12:15 amSeattle/Tacoma Intl
Mar 28
SEA5:00 amSeattle/Tacoma Intl
3h 55m
MDW10:55 amChicago Midway
$180
Southwest
Mar 11
MDW5:45 amChicago Midway
10h 05m
1 stop
SEA1:50 pmSeattle/Tacoma Intl
Mar 18
SEA8:25 pmSeattle/Tacoma Intl
7h 20m
1 stop
MDW5:45 amChicago Midway
$181

momondo Fare Finder

 
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, momondo users made 832,500 searches. Data last updated March 2, 2026.
Use the filters below to find and compare flights from Illinois to Seattle that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Tue 4/21

5:21 pm-12:36 am

1 stop9h 15m

Seattle/Tacoma Intl

Sat 4/25

7:00 am-4:41 pm

1 stop7h 41m

$177

ChicagoSeattle

MDW - SEA

MDWSEA

Chicago Midway

Sat 5/2

6:15 am-5:55 pm

1 stop13h 40m

Seattle/Tacoma Intl

Sat 5/9

11:55 pm-5:55 am

Nonstop4h 00m

$179

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Tue 4/28

11:07 am-9:27 am

2 stops24h 20m

Seattle/Tacoma Intl

Wed 5/6

10:42 am-5:50 am

1 stop17h 08m

$179

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Thu 4/30

6:20 am-5:42 pm

1 stop13h 22m

Seattle/Tacoma Intl

Sun 5/3

10:25 pm-5:50 am

1 stop29h 25m

$180

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Fri 4/24

8:06 pm-9:27 am

1 stop15h 21m

Seattle/Tacoma Intl

Sat 5/2

7:12 pm-7:21 pm

1 stop22h 09m

$181

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Fri 5/1

5:15 am-8:51 pm

2 stops17h 36m

Seattle/Tacoma Intl

Mon 5/4

9:19 pm-6:47 am

1 stop31h 28m

$181

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Wed 5/6

12:46 pm-3:20 pm

Nonstop4h 34m

Seattle/Tacoma Intl

Sun 5/10

6:00 am-4:51 pm

1 stop8h 51m

$182

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Fri 5/1

5:35 pm-11:54 pm

1 stop8h 19m

Seattle/Tacoma Intl

Mon 5/11

1:25 pm-12:30 am

1 stop9h 05m

$185

PeoriaSeattle

PIA - SEA

PIASEA

Greater Peoria

Wed 7/1

5:33 pm-10:39 pm

1 stop7h 06m

Seattle/Tacoma Intl

Wed 7/8

11:52 pm-10:10 am

1 stop8h 18m

$309

MolineSeattle

MLI - SEA

MLISEA

Moline Quad-City

Thu 4/23

7:34 pm-12:34 am

1 stop7h 00m

Seattle/Tacoma Intl

Sat 5/2

8:38 am-9:02 pm

2 stops10h 24m

$314

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to Seattle from

How to get the cheapest flight ticket from Illinois to Seattle

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the cheapest month to fly to Seattle?

In general, January is the cheapest month to fly from Illinois to Seattle. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $209. If you don’t want to visit Seattle in January, then you should wait until April to fly from Illinois, when ticket prices are also cheap, with an average price of $238.

What is the cheapest day to depart on your flight to Seattle?

On average, the least expensive day to fly to Seattle from Illinois is on a Wednesday. momondo users have found tickets for Wednesday departures for as low as $319. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Monday is the most expensive day to depart from Illinois because it is more convenient for both business and leisure travelers. As a result, prices tend to be around $429.

What is the cheapest time of day to depart on your flight to Seattle?

Flying to Seattle from Illinois in the evening is the least expensive time of day to depart. momondo users have found prices as low as $311 when looking at flights departing in the evening. Flights to Seattle are more costly in the afternoon, with an average ticket price of $355. Departure times in the afternoon fall within the peak daily travel times, which is why tickets can be more expensive.

What is the cheapest Illinois to Seattle/Tacoma Intl flight route?

Fly from Chicago Midway to Seattle/Tacoma Intl for the best Illinois - Seattle/Tacoma Intl flight prices

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

You are more likely to see cheaper flights to Seattle from Illinois when booking weeks ahead of your departure date. In general, you can expect to find flights to Seattle for around $277 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Seattle from Illinois for as low as $241 on momondo.

What cabin class options are available on Illinois to Seattle/Tacoma Intl flights?

There are 4 cabin classes available to choose from on Illinois to Seattle/Tacoma Intl flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Illinois to Seattle flights?

No. A direct flight is the cheapest option for a flight between Illinois to Seattle.

Cheap Illinois to Seattle flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Illinois to Seattle

Best Price Found

$117

Fastest flight time

4h 15m

Direct flights

Every day

Airports in Seattle

1 airport
The best one-way flight to Seattle from Illinois in the past 72 hours is $117. The best round-trip flight deal from Illinois to Seattle found on momondo in the last 72 hours is $217.
The fastest flight from Illinois to Seattle takes 4h 15m
Direct flights go from Illinois to Seattle every day.
There is 1 airport in Seattle. From Illinois there are direct flights to Seattle/Tacoma Intl (SEA).
Search flight deals

  • When did momondo last update prices for flights from Illinois to Seattle/Tacoma Intl Airport?

    Prices for flights from Illinois to Seattle/Tacoma Intl Airport refresh daily.

  • How many operators does momondo search for flights from Illinois to Seattle/Tacoma Intl Airport?

  • How old do you have to be to fly from Illinois to Seattle/Tacoma Intl Airport?

    Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Illinois to Seattle/Tacoma Intl Airport.

  • What documentation or ID do you need to fly to Seattle/Tacoma Intl Airport?

    The required travel and health documents for your Seattle/Tacoma Intl Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Seattle/Tacoma Intl Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

  • What is the most popular plane model from Illinois to Seattle?

Best airlines flying from Illinois to Seattle

Compare and see reviews for airlines that fly from Illinois to Seattle with momondo
Airline
Rating
Free Cancellation
Price
Hawaiian AirlinesPriceFrom $84Free CancellationRating
7.8
2,837 reviews
Search Hawaiian Airlines flights
DeltaPriceFrom $109Free CancellationRating
7.9
8,237 reviews
Search Delta flights
FrontierPriceFrom $153Free CancellationRating
5.7
3,041 reviews
Search Frontier flights
United AirlinesPriceFrom $167Free CancellationRating
7.4
9,375 reviews
Search United Airlines flights
Alaska AirlinesPriceFrom $168Free CancellationRating
8.0
11,974 reviews
Search Alaska Airlines flights
American AirlinesPriceFrom $171Free CancellationRating
7.1
11,369 reviews
Search American Airlines flights
SouthwestPriceFrom $194Free CancellationRating
8.0
4,307 reviews
Search Southwest flights

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
Tacoma
Leavenworth
SeaTac
Ocean Shores
Renton
Olympia
Lynnwood
Kent
Marysville
Redmond
Puyallup
Cle Elum
Lakewood
Tukwila
Federal Way
Fife
Westport
Kirkland
Centralia
Tumwater

Why use momondo?

Why should I use momondo to find a flight deal from Illinois to Seattle?

Finding the right flight to Seattle from Illinois is quick and easy when you have a range of options in front of you, from reputable agents and recognisable airlines. Options that can then be filtered down to find the best fit. That is what momondo does. We make finding flights to Seattle quick and easy, saving you time and money.

Can I find flights from Illinois to Seattle with flexible booking policies on momondo?

Yes. momondo enables you to select and highlight flights to Seattle from Illinois with this policy.

How can momondo help me find flights from Illinois to Seattle?

Once you have performed a search for Illinois to Seattle flights, momondo helps you find the right one by offering useful filters to narrow down your flight selection. Flights can be filtered by multiple factors such as airline, airport and price; but also by other criteria like aircraft type and payment method.

I’m not ready to book a flight from Illinois to Seattle right now. Can momondo alert me if prices change?

If you are not ready to book a flight from Illinois to Seattle now, use our insights above to find helpful tips or alternatively set up a price alert, where momondo will track prices on flights to Seattle and let you know when they change.

An easier way to manage your Seattle trip

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