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Cheap flights from Illinois to Seattle from $86

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 5/7. 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.
Frontier Logo
5:50 am - 9:27 am
ORD
-
SEA
29h 37m
2 stops
Frontier Logo
11:06 am - 6:39 am
SEA
-
ORD
17h 33m
1 stop
$226Frontier
Fri, May 1 - Tue, May 5
Multiple Airlines Logo
11:28 am - 3:05 pm
ORD
-
SEA
29h 37m
2 stops
Multiple Airlines Logo
11:06 am - 6:39 am
SEA
-
ORD
17h 33m
1 stop
$228Multiple Airlines
Thu, Apr 30 - Tue, May 5
Frontier Logo
9:04 pm - 6:35 pm
ORD
-
SEA
23h 31m
1 stop
Frontier Logo
11:03 am - 6:19 am
SEA
-
ORD
17h 16m
1 stop
$230Frontier
Sat, Jun 6 - Sun, Jun 14
Multiple Airlines Logo
11:28 am - 9:27 am
ORD
-
SEA
23h 59m
2 stops
Multiple Airlines Logo
11:06 am - 6:39 am
SEA
-
ORD
17h 33m
1 stop
$238Multiple Airlines
Fri, May 1 - Tue, May 5
United Airlines Logo
7:09 pm - 11:59 pm
STL
-
SEA
6h 50m
1 stop
United Airlines Logo
8:45 am - 6:17 pm
SEA
-
STL
7h 32m
1 stop
$249United Airlines
Wed, May 13 - Sat, May 23
Southwest Logo
6:05 pm - 8:35 pm
MDW
-
SEA
4h 30mnonstop
Southwest Logo
11:55 pm - 5:55 am
SEA
-
MDW
4h 00mnonstop
$255Southwest
Sat, May 9 - Sat, May 16
Southwest Logo
10:00 am - 5:55 pm
MDW
-
SEA
9h 55m
1 stop
Southwest Logo
11:55 pm - 5:55 am
SEA
-
MDW
4h 00mnonstop
$265Southwest
Sat, May 9 - Sat, May 16
American Airlines Logo
6:54 pm - 12:36 am
PIA
-
SEA
7h 42m
1 stop
American Airlines Logo
3:17 pm - 11:37 pm
SEA
-
PIA
6h 20m
1 stop
$271American Airlines
Wed, May 13 - Wed, May 20
United Airlines Logo
5:30 pm - 10:47 pm
PIA
-
SEA
7h 17m
1 stop
United Airlines Logo
10:53 pm - 10:10 am
SEA
-
PIA
9h 17m
1 stop
$281United Airlines
Wed, May 13 - Wed, May 20
American Airlines Logo
3:01 pm - 9:22 pm
CMI
-
SEA
8h 21m
1 stop
American Airlines Logo
7:10 am - 6:24 pm
SEA
-
CMI
9h 14m
1 stop
$306American Airlines
Thu, May 7 - Sun, May 10

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Frontier flights from Illinois to Seattle

Our best Frontier deals on Illinois to Seattle flight tickets
Frontier
May 1
ORD5:50 amChicago O'Hare Intl
29h 37m
2 stops
SEA9:27 amSeattle/Tacoma Intl
May 5
SEA11:06 amSeattle/Tacoma Intl
17h 33m
1 stop
ORD6:39 amChicago O'Hare Intl
$226
Frontier
Jun 6
ORD9:04 pmChicago O'Hare Intl
23h 31m
1 stop
SEA6:35 pmSeattle/Tacoma Intl
Jun 14
SEA11:03 amSeattle/Tacoma Intl
17h 16m
1 stop
ORD6:19 amChicago O'Hare Intl
$230
Frontier
Apr 30
STL9:55 pmLambert-St Louis
24h 56m
1 stop
SEA8:51 pmSeattle/Tacoma Intl
May 3
SEA7:12 pmSeattle/Tacoma Intl
22h 20m
1 stop
STL7:32 pmLambert-St Louis
$231

Southwest flights from Illinois to Seattle

Our best Southwest deals on Illinois to Seattle flight tickets
Southwest
May 9
MDW6:05 pmChicago Midway
4h 30m
SEA8:35 pmSeattle/Tacoma Intl
May 16
SEA11:55 pmSeattle/Tacoma Intl
4h 00m
MDW5:55 amChicago Midway
$255
Southwest
May 9
MDW10:00 amChicago Midway
9h 55m
1 stop
SEA5:55 pmSeattle/Tacoma Intl
May 16
SEA11:55 pmSeattle/Tacoma Intl
4h 00m
MDW5:55 amChicago Midway
$265
Southwest
May 9
MDW10:15 amChicago Midway
10h 00m
2 stops
SEA6:15 pmSeattle/Tacoma Intl
May 16
SEA11:55 pmSeattle/Tacoma Intl
4h 00m
MDW5:55 amChicago Midway
$270

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 April 17, 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

Cheapest round-trip

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Fri 5/1

5:50 am-9:27 am

2 stops29h 37m

Seattle/Tacoma Intl

Tue 5/5

11:06 am-6:39 am

1 stop17h 33m

$226

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Thu 4/30

11:28 am-3:05 pm

2 stops29h 37m

Seattle/Tacoma Intl

Tue 5/5

11:06 am-6:39 am

1 stop17h 33m

$228

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Sat 6/6

9:04 pm-6:35 pm

1 stop23h 31m

Seattle/Tacoma Intl

Sun 6/14

11:03 am-6:19 am

1 stop17h 16m

$230

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Fri 5/1

11:28 am-9:27 am

2 stops23h 59m

Seattle/Tacoma Intl

Tue 5/5

11:06 am-6:39 am

1 stop17h 33m

$238

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Wed 5/13

7:09 pm-11:59 pm

1 stop6h 50m

Seattle/Tacoma Intl

Sat 5/23

8:45 am-6:17 pm

1 stop7h 32m

$249
Quickest round-trip

ChicagoSeattle

MDW - SEA

MDWSEA

Chicago Midway

Sat 5/9

6:05 pm-8:35 pm

Nonstop4h 30m

Seattle/Tacoma Intl

Sat 5/16

11:55 pm-5:55 am

Nonstop4h 00m

$255

ChicagoSeattle

MDW - SEA

MDWSEA

Chicago Midway

Sat 5/9

10:00 am-5:55 pm

1 stop9h 55m

Seattle/Tacoma Intl

Sat 5/16

11:55 pm-5:55 am

Nonstop4h 00m

$265

PeoriaSeattle

PIA - SEA

PIASEA

Greater Peoria

Wed 5/13

6:54 pm-12:36 am

1 stop7h 42m

Seattle/Tacoma Intl

Wed 5/20

3:17 pm-11:37 pm

1 stop6h 20m

$271

PeoriaSeattle

PIA - SEA

PIASEA

Greater Peoria

Wed 5/13

5:30 pm-10:47 pm

1 stop7h 17m

Seattle/Tacoma Intl

Wed 5/20

10:53 pm-10:10 am

1 stop9h 17m

$281

ChampaignSeattle

CMI - SEA

CMISEA

Champaign University-Willard

Thu 5/7

3:01 pm-9:22 pm

1 stop8h 21m

Seattle/Tacoma Intl

Sun 5/10

7:10 am-6:24 pm

1 stop9h 14m

$306

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 February to fly from Illinois, when ticket prices are also cheap, with an average price of $235.

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 $328. 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 $441.

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 $320 when looking at flights departing in the evening. Flights to Seattle are more costly in the afternoon, with an average ticket price of $377. 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 O'Hare Intl 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 $285 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 $249 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?

You could potentially save up to 30% on your flight if you consider stops on a Illinois to Seattle flight.

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

$183

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 $183. The best round-trip flight deal from Illinois to Seattle found on momondo in the last 72 hours is $276.
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

Frequently asked questions about flying from Illinois to Seattle

  • 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
2,839 reviews
Search Hawaiian Airlines flights
DeltaPriceFrom $107Free CancellationRating
7.9
8,409 reviews
Search Delta flights
FrontierPriceFrom $153Free CancellationRating
5.7
2,987 reviews
Search Frontier flights
Alaska AirlinesPriceFrom $168Free CancellationRating
7.9
12,253 reviews
Search Alaska Airlines flights
American AirlinesPriceFrom $173Free CancellationRating
7.1
11,593 reviews
Search American Airlines flights
United AirlinesPriceFrom $177Free CancellationRating
7.4
9,602 reviews
Search United Airlines flights
SouthwestPriceFrom $194Free CancellationRating
8.0
4,328 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
Redmond
Marysville
Lakewood
Tukwila
Puyallup
Cle Elum
Federal Way
Centralia
Fife
Westport
Shoreline
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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