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Cheap flights from Seattle to Illinois from $61

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 12/5. 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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Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
12:58 pm - 12:15 amSEA-ORD
9h 17m1 stop
Frontier Logo
6:00 am - 12:13 pmORD-SEA
8h 13m1 stop
$182Frontier
Find Deal
Thu, Nov 13 - Sun, Nov 16
Frontier Logo
12:58 pm - 11:29 pmSEA-ORD
8h 31m1 stop
Frontier Logo
2:42 pm - 12:13 pmORD-SEA
23h 31m2 stops
$183Frontier
Find Deal
Sat, Nov 8 - Thu, Nov 13
Alaska Airlines Logo
12:18 am - 6:21 amSEA-ORD
4h 03mnonstop
Alaska Airlines Logo
8:00 am - 10:52 amORD-SEA
4h 52mnonstop
$187Alaska Airlines
Find Deal
Wed, Dec 10 - Wed, Dec 17
Alaska Airlines Logo
5:49 pm - 11:59 pmSEA-ORD
4h 10mnonstop
Alaska Airlines Logo
6:08 pm - 8:58 pmORD-SEA
4h 50mnonstop
$192Alaska Airlines
Find Deal
Wed, Dec 31 - Mon, Jan 5
United Airlines Logo
11:59 pm - 6:09 amSEA-ORD
4h 10mnonstop
United Airlines Logo
4:05 pm - 6:46 pmORD-SEA
4h 41mnonstop
$223United Airlines
Find Deal
Sat, Dec 27 - Wed, Dec 31
Delta Logo
5:55 pm - 11:59 pmSEA-ORD
4h 04mnonstop
Delta Logo
7:50 am - 10:41 amORD-SEA
4h 51mnonstop
$229Delta
Find Deal
Thu, Dec 4 - Wed, Dec 10
Delta Logo
9:30 am - 6:57 pmSEA-STL
7h 27m1 stop
Delta Logo
7:47 pm - 12:11 amSTL-SEA
6h 24m1 stop
$233Delta
Find Deal
Thu, Nov 13 - Sun, Nov 16
United Airlines Logo
3:45 pm - 11:59 pmSEA-ORD
6h 14m1 stop
United Airlines Logo
1:25 pm - 4:07 pmORD-SEA
4h 42mnonstop
$235United Airlines
Find Deal
Thu, Dec 4 - Sun, Dec 7
American Airlines Logo
12:31 am - 10:37 amSEA-STL
8h 06m1 stop
American Airlines Logo
4:49 pm - 11:25 pmSTL-SEA
8h 36m1 stop
$247American Airlines
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Wed, Dec 10 - Sun, Dec 14
American Airlines Logo
12:31 am - 10:37 amSEA-STL
8h 06m1 stop
American Airlines Logo
11:35 am - 5:51 pmSTL-SEA
8h 16m1 stop
$258American Airlines
Find Deal
Wed, Dec 3 - Wed, Dec 10

Hawaiian Airlines flights from Seattle to Illinois

Our best Hawaiian Airlines deals on Seattle to Illinois flight tickets
Hawaiian Airlines
Dec 4
SEA5:50 pmSeattle/Tacoma Intl
4h 09m
ORD11:59 pmChicago O'Hare Intl
Dec 10
ORD3:35 pmChicago O'Hare Intl
4h 47m
SEA6:22 pmSeattle/Tacoma Intl
$198
Find similar
Hawaiian Airlines
Dec 13
SEA2:08 pmSeattle/Tacoma Intl
7h 42m
1 stop
ORD11:50 pmChicago O'Hare Intl
Dec 15
ORD3:05 pmChicago O'Hare Intl
8h 38m
1 stop
SEA9:43 pmSeattle/Tacoma Intl
$224
Find similar
Hawaiian Airlines
Dec 9
SEA8:34 amSeattle/Tacoma Intl
3h 53m
STL2:27 pmLambert-St Louis
Dec 16
STL7:00 amLambert-St Louis
4h 40m
SEA9:40 amSeattle/Tacoma Intl
$234
Find similar

Frontier flights from Seattle to Illinois

Our best Frontier deals on Seattle to Illinois flight tickets
Frontier
Nov 13
SEA12:58 pmSeattle/Tacoma Intl
9h 17m
1 stop
ORD12:15 amChicago O'Hare Intl
Nov 16
ORD6:00 amChicago O'Hare Intl
8h 13m
1 stop
SEA12:13 pmSeattle/Tacoma Intl
$182
Find similar
Frontier
Nov 8
SEA12:58 pmSeattle/Tacoma Intl
8h 31m
1 stop
ORD11:29 pmChicago O'Hare Intl
Nov 13
ORD2:42 pmChicago O'Hare Intl
23h 31m
2 stops
SEA12:13 pmSeattle/Tacoma Intl
$183
Find similar
Frontier
Nov 13
SEA12:58 pmSeattle/Tacoma Intl
9h 17m
1 stop
ORD12:15 amChicago O'Hare Intl
Nov 27
ORD6:45 pmChicago O'Hare Intl
20h 37m
1 stop
SEA1:22 pmSeattle/Tacoma Intl
$185
Find similar

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 October 27, 2025.
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

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Thu 11/13

12:58 pm-12:15 am

1 stop9h 17m

Chicago O'Hare Intl

Sun 11/16

6:00 am-12:13 pm

1 stop8h 13m

$182

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Sat 11/8

12:58 pm-11:29 pm

1 stop8h 31m

Chicago O'Hare Intl

Thu 11/13

2:42 pm-12:13 pm

2 stops23h 31m

$183

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Wed 12/10

12:18 am-6:21 am

Nonstop4h 03m

Chicago O'Hare Intl

Wed 12/17

8:00 am-10:52 am

Nonstop4h 52m

$187

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Wed 12/31

5:49 pm-11:59 pm

Nonstop4h 10m

Chicago O'Hare Intl

Mon 1/5

6:08 pm-8:58 pm

Nonstop4h 50m

$192

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Sat 12/27

11:59 pm-6:09 am

Nonstop4h 10m

Chicago O'Hare Intl

Wed 12/31

4:05 pm-6:46 pm

Nonstop4h 41m

$223

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Thu 12/4

5:55 pm-11:59 pm

Nonstop4h 04m

Chicago O'Hare Intl

Wed 12/10

7:50 am-10:41 am

Nonstop4h 51m

$229

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 11/13

9:30 am-6:57 pm

1 stop7h 27m

Lambert-St Louis

Sun 11/16

7:47 pm-12:11 am

1 stop6h 24m

$233

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

Thu 12/4

3:45 pm-11:59 pm

1 stop6h 14m

Chicago O'Hare Intl

Sun 12/7

1:25 pm-4:07 pm

Nonstop4h 42m

$235

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Wed 12/10

12:31 am-10:37 am

1 stop8h 06m

Lambert-St Louis

Sun 12/14

4:49 pm-11:25 pm

1 stop8h 36m

$247

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Wed 12/3

12:31 am-10:37 am

1 stop8h 06m

Lambert-St Louis

Wed 12/10

11:35 am-5:51 pm

1 stop8h 16m

$258

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 January. Flight prices, which tend to average around $225, 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 January, then flying in February is also cheap. Prices for this month can be found on momondo for an average of $264.

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

The cheapest day to depart from Seattle to Illinois is on a Wednesday when prices can be found for as low as $396. Flights from Seattle to Illinois on a Sunday will generally be more expensive and average around $501. 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 $289. Flights in the morning are often more expensive with an average ticket price of $454.

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 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 $310 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 $267 on momondo.

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

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

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

$170

Fastest flight time

3h 50m

Direct flights

Every day

Airports in Illinois

3 airports
The best one-way flight to Illinois from Seattle in the past 72 hours is $170. The best round-trip flight deal from Seattle to Illinois found on momondo in the last 72 hours is $310.
The fastest flight from Seattle to Illinois takes 3h 50m
Direct flights go from Seattle to Illinois every day.
There are 3 airports near Illinois: Chicago O'Hare Intl (ORD), Chicago Midway (MDW), Lambert-St Louis (STL)
Search flight deals

  • 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
Spirit AirlinesPriceFrom $107Free CancellationRating
6.3
8,112 reviews
Search Spirit Airlines flights
Hawaiian AirlinesPriceFrom $121Free CancellationRating
7.8
2,792 reviews
Search Hawaiian Airlines flights
DeltaPriceFrom $126Free CancellationRating
7.9
7,996 reviews
Search Delta flights
FrontierPriceFrom $137Free CancellationRating
5.8
3,123 reviews
Search Frontier flights
United AirlinesPriceFrom $167Free CancellationRating
7.4
8,999 reviews
Search United Airlines flights
Alaska AirlinesPriceFrom $176Free CancellationRating
8.0
11,193 reviews
Search Alaska Airlines flights
SouthwestPriceFrom $179Free CancellationRating
8.0
4,238 reviews
Search Southwest flights
American AirlinesPriceFrom $180Free CancellationRating
7.2
11,031 reviews
Search American Airlines 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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