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Cheap flights from Seattle to Illinois from $94

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Seattle to Illinois departing on 10/24. 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
1 adult, Economy, 0 bags

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Seattle to Illinois

Cheap round-trip flights

Enter your travel dates to find the best prices.
American Airlines Logo
1:40 pm - 12:08 am
SEA
-
PIA
8h 28m
1 stop
American Airlines Logo
5:28 pm - 12:11 am
PIA
-
SEA
8h 43m
1 stop
$281American Airlines
Wed, Sep 16 - Sat, Sep 19
United Airlines Logo
11:00 pm - 10:06 am
SEA
-
PIA
9h 06m
1 stop
United Airlines Logo
8:45 am - 4:14 pm
PIA
-
SEA
9h 29m
2 stops
$286United Airlines
Sat, Sep 5 - Sat, Sep 12
Southwest Logo
11:10 am - 9:50 pm
SEA
-
MDW
8h 40m
1 stop
Southwest Logo
10:05 pm - 12:35 am
MDW
-
SEA
4h 30mnonstop
$309Southwest
Thu, Oct 1 - Thu, Oct 8
Southwest Logo
11:40 am - 9:05 pm
SEA
-
MDW
7h 25m
1 stop
Southwest Logo
10:10 am - 5:30 pm
MDW
-
SEA
9h 20m
2 stops
$311Southwest
Tue, Aug 25 - Wed, Aug 26
American Airlines Logo
3:35 pm - 11:59 pm
SEA
-
PIA
6h 24m
1 stop
American Airlines Logo
6:47 pm - 12:13 am
PIA
-
SEA
7h 26m
1 stop
$320American Airlines
Thu, Aug 27 - Sat, Sep 5
United Airlines Logo
1:57 pm - 10:43 pm
SEA
-
PIA
6h 46m
1 stop
United Airlines Logo
8:45 am - 6:29 pm
PIA
-
SEA
11h 44m
2 stops
$325United Airlines
Fri, Aug 28 - Sat, Sep 5
Alaska Airlines Logo
8:13 am - 2:21 pm
SEA
-
STL
4h 08mnonstop
Alaska Airlines Logo
6:08 pm - 10:39 pm
STL
-
SEA
6h 31m
1 stop
$347Alaska Airlines
Wed, Sep 16 - Tue, Sep 22
Delta Logo
10:59 pm - 11:18 am
SEA
-
BMI
10h 19m
1 stop
Delta Logo
4:32 pm - 11:58 pm
BMI
-
SEA
9h 26m
1 stop
$356Delta
Tue, Sep 22 - Mon, Sep 28
Alaska Airlines Logo
8:05 am - 2:04 pm
SEA
-
STL
3h 59mnonstop
Alaska Airlines Logo
6:35 am - 9:02 am
STL
-
SEA
4h 27mnonstop
$360Alaska Airlines
Wed, Sep 2 - Sun, Sep 6
Delta Logo
11:05 pm - 11:18 am
SEA
-
BMI
10h 13m
2 stops
Delta Logo
4:32 pm - 11:58 pm
BMI
-
SEA
9h 26m
1 stop
$361Delta
Tue, Sep 22 - Mon, Sep 28

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Frontier flights from Seattle to Illinois

Our best Frontier deals on Seattle to Illinois flight tickets
Frontier
Aug 18
SEA7:06 pmSeattle/Tacoma Intl
18h 53m
2 stops
ORD3:59 pmChicago O'Hare Intl
Aug 25
ORD2:41 pmChicago O'Hare Intl
20h 38m
1 stop
SEA9:19 amSeattle/Tacoma Intl
$297
Frontier
Sep 7
SEA9:36 pmSeattle/Tacoma Intl
18h 45m
1 stop
ORD6:21 pmChicago O'Hare Intl
Sep 14
ORD6:20 amChicago O'Hare Intl
19h 38m
2 stops
SEA11:58 pmSeattle/Tacoma Intl
$298
Frontier
Oct 9
SEA7:00 pmSeattle/Tacoma Intl
8h 42m
1 stop
ORD5:42 amChicago O'Hare Intl
Oct 12
ORD6:50 amChicago O'Hare Intl
12h 55m
1 stop
SEA5:45 pmSeattle/Tacoma Intl
$299

Delta flights from Seattle to Illinois

Our best Delta deals on Seattle to Illinois flight tickets
Delta
Aug 14
SEA10:50 amSeattle/Tacoma Intl
4h 10m
ORD5:00 pmChicago O'Hare Intl
Sep 16
ORD12:50 pmChicago O'Hare Intl
4h 35m
SEA3:25 pmSeattle/Tacoma Intl
$300
Delta
Aug 13
SEA7:15 amSeattle/Tacoma Intl
4h 08m
ORD1:23 pmChicago O'Hare Intl
Aug 14
ORD7:00 amChicago O'Hare Intl
4h 37m
SEA9:37 amSeattle/Tacoma Intl
$313
Delta
Sep 22
SEA10:59 pmSeattle/Tacoma Intl
10h 19m
1 stop
BMI11:18 amBloomington-Normal
Sep 28
BMI4:32 pmBloomington-Normal
9h 26m
1 stop
SEA11:58 pmSeattle/Tacoma Intl
$356

momondo Fare Finder

 
Customize your flight search to find flights from Seattle to Illinois 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 July 27, 2026.
Use the filters below to find and compare flights from Seattle to Illinois that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattlePeoria

SEA - PIA

SEAPIA

Seattle/Tacoma Intl

Wed 9/16

1:40 pm-12:08 am

1 stop8h 28m

Greater Peoria

Sat 9/19

5:28 pm-12:11 am

1 stop8h 43m

$281

SeattlePeoria

SEA - PIA

SEAPIA

Seattle/Tacoma Intl

Sat 9/5

11:00 pm-10:06 am

1 stop9h 06m

Greater Peoria

Sat 9/12

8:45 am-4:14 pm

2 stops9h 29m

$286

SeattleChicago

SEA - MDW

SEAMDW

Seattle/Tacoma Intl

Thu 10/1

11:10 am-9:50 pm

1 stop8h 40m

Chicago Midway

Thu 10/8

10:05 pm-12:35 am

Nonstop4h 30m

$309

SeattleChicago

SEA - MDW

SEAMDW

Seattle/Tacoma Intl

Tue 8/25

11:40 am-9:05 pm

1 stop7h 25m

Chicago Midway

Wed 8/26

10:10 am-5:30 pm

2 stops9h 20m

$311

SeattlePeoria

SEA - PIA

SEAPIA

Seattle/Tacoma Intl

Thu 8/27

3:35 pm-11:59 pm

1 stop6h 24m

Greater Peoria

Sat 9/5

6:47 pm-12:13 am

1 stop7h 26m

$320

SeattlePeoria

SEA - PIA

SEAPIA

Seattle/Tacoma Intl

Fri 8/28

1:57 pm-10:43 pm

1 stop6h 46m

Greater Peoria

Sat 9/5

8:45 am-6:29 pm

2 stops11h 44m

$325

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Wed 9/16

8:13 am-2:21 pm

Nonstop4h 08m

Lambert-St Louis

Tue 9/22

6:08 pm-10:39 pm

1 stop6h 31m

$347

SeattleBloomington

SEA - BMI

SEABMI

Seattle/Tacoma Intl

Tue 9/22

10:59 pm-11:18 am

1 stop10h 19m

Bloomington-Normal

Mon 9/28

4:32 pm-11:58 pm

1 stop9h 26m

$356
Quickest round-trip

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Wed 9/2

8:05 am-2:04 pm

Nonstop3h 59m

Lambert-St Louis

Sun 9/6

6:35 am-9:02 am

Nonstop4h 27m

$360

SeattleBloomington

SEA - BMI

SEABMI

Seattle/Tacoma Intl

Tue 9/22

11:05 pm-11:18 am

2 stops10h 13m

Bloomington-Normal

Mon 9/28

4:32 pm-11:58 pm

1 stop9h 26m

$361

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 Illinois from

How to get the cheapest flight ticket from Seattle to Illinois

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 Illinois?

The cheapest month to fly to Illinois from Seattle is in February. Flight prices, which tend to average around $262, are often lower during this time because this is during the off-season. If you aren’t able to travel to Illinois during the month of February, then flying in January is also cheap. Prices for this month can be found on momondo for an average of $274.

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

The cheapest day to depart from Seattle to Illinois is on a Thursday when prices can be found for as low as $423. Flights from Seattle to Illinois on a Sunday will generally be more expensive and average around $517. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

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

Our most recent data shows that the best time of day to fly to Illinois is in the afternoon. Flights from Seattle to Illinois during this time can be as low as $364. Flights in the morning are often more expensive with an average ticket price of $458.

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

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

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

You are more likely to see cheaper flights to Illinois from Seattle when booking weeks ahead of your departure date. In general, you can expect to find flights to Illinois for around $333 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Illinois from Seattle for as low as $291 on momondo.

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

There are 4 cabin classes available to choose from on Seattle to Illinois 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 Seattle to Illinois flights?

You could potentially save up to 34% on your flight if you consider stops on a Seattle to Illinois flight.

Cheap Seattle to Illinois flight deals and tips

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

Best Price Found

$208

Fastest flight time

3h 50m

Direct flights

Every day

Airports in Illinois

98 airports
The best one-way flight to Illinois from Seattle in the past 72 hours is $208. The best round-trip flight deal from Seattle to Illinois found on momondo in the last 72 hours is $384.
The fastest flight from Seattle to Illinois takes 3h 50m
Direct flights go from Seattle to Illinois every day.
There are 98 airports in Illinois. From Seattle there are direct flights to Chicago O'Hare Intl (ORD), Chicago Midway (MDW), Lambert-St Louis (STL).
Search flight deals

Frequently asked questions about flying from Seattle to Illinois

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

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

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

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

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Seattle/Tacoma Intl Airport to Illinois.

  • What documentation or ID do you need to fly to Illinois?

    The necessary travel and health documents for your Illinois trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

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

Best airlines flying from Seattle to Illinois

Compare and see reviews for airlines that fly from Seattle to Illinois with momondo
Airline
Rating
Free Cancellation
Price
Hawaiian AirlinesPriceFrom $118Free CancellationRating
7.8
2,821 reviews
Search Hawaiian Airlines flights
DeltaPriceFrom $133Free CancellationRating
7.8
8,483 reviews
Search Delta flights
Alaska AirlinesPriceFrom $177Free CancellationRating
7.9
12,718 reviews
Search Alaska Airlines flights
United AirlinesPriceFrom $182Free CancellationRating
7.4
10,041 reviews
Search United Airlines flights
American AirlinesPriceFrom $182Free CancellationRating
7.1
11,837 reviews
Search American Airlines flights
FrontierPriceFrom $193Free CancellationRating
5.6
2,754 reviews
Search Frontier flights
SouthwestPriceFrom $239Free CancellationRating
8.0
4,228 reviews
Search Southwest flights

Why use momondo?

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

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from Seattle to Illinois. Millions of users trust and use momondo every year so you are in good hands.

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

All flight searches from Seattle to Illinois on momondo can be filtered to show those which offer flexible booking policies.

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

Once all potential Seattle to Illinois flight options are in front of you, momondo lets you sort and filter flights based on preferences such as airline, price and flight times amongst many other options.

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

Price alerts on flights to Illinois from Seattle are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

An easier way to manage your Illinois trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.
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