What is the cheapest airline that flies from Illinois to Seattle/Tacoma Intl?

Frontier, American Airlines, and Southwest are the most popular carriers operating from Illinois to Seattle/Tacoma Intl

What airlines fly to Seattle?

Alaska Airlines, American Airlines and Delta are the top three most popular airlines that fly to Seattle from Illinois according to our data. Alaska Airlines is the first choice among our users, with 31% of people opting to fly with this airline when traveling to Seattle. Keep in mind that there are 8 different airlines that fly to Seattle on a routine basis, so you have a few additional options to choose from.

How many flights depart from Illinois to Seattle on average per week?

As of December 2025, there are 290 flights per week flying from Illinois to Seattle. The most common day of the week flights depart is Thu, with 18% of flights taking off on this day.

How long does it take to fly to Seattle?

Flight times vary depending on what airport in Illinois you fly out of and what airport in Seattle you fly into. For example, flying from Chicago to Seattle takes 4h 32m on average. On the other hand, flying from Moline to Seattle takes 6h 48m on average. Keep in mind that it’s always quicker to opt for a non-stop flight, so be sure to check momondo if there are any available for your route.

How many flights depart from Illinois to Seattle on average per day?

41 flights are operational daily from Illinois to Seattle as of December 2025. The most popular departure time for this route is 8:00PM, with 39% of flights per day taking off at noon.

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?

As of December 2025, there are 8 operators available to choose from 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.

$68 Cheap Flights from Illinois to Seattle in 2025/26

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Find the cheapest flights from Illinois to Seattle

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

10:35 am - 1:15 pm

MDW

SEA

4h 40mnonstop

6:45 am - 12:40 pm

SEA

MDW

3h 55mnonstop

$177Southwest

Mon, Jan 12 - Sun, Jan 18

8:50 am - 11:32 am

ORD

SEA

4h 42mnonstop

10:58 am - 5:03 pm

SEA

ORD

4h 05mnonstop

$177United Airlines

Thu, Jan 15 - Sun, Jan 18

1:09 pm - 3:57 pm

ORD

SEA

4h 48mnonstop

9:00 pm - 5:02 am

SEA

ORD

6h 02m1 stop

$178Alaska Airlines

Tue, Jan 6 - Tue, Jan 6

2:06 pm - 6:43 pm

ORD

SEA

6h 37m1 stop

8:30 am - 2:38 pm

SEA

ORD

4h 08mnonstop

$179Multiple Airlines

Fri, Jan 23 - Fri, Jan 30

3:35 pm - 6:22 pm

ORD

SEA

4h 47mnonstop

12:19 pm - 9:24 pm

SEA

ORD

7h 05m1 stop

$180Multiple Airlines

Thu, Jan 8 - Thu, Jan 15

7:36 pm - 10:20 pm

ORD

SEA

4h 44mnonstop

8:04 am - 2:15 pm

SEA

ORD

4h 11mnonstop

$181American Airlines

Sun, Jan 11 - Wed, Jan 14

3:44 pm - 10:15 pm

ORD

SEA

8h 31m1 stop

5:50 pm - 11:50 pm

SEA

ORD

4h 00mnonstop

$182Hawaiian Airlines

Thu, Jan 8 - Wed, Jan 14

7:54 pm - 10:43 pm

ORD

SEA

4h 49mnonstop

12:35 pm - 11:14 pm

SEA

ORD

8h 39m1 stop

$183United Airlines

Thu, Jan 8 - Mon, Jan 12

2:06 pm - 6:43 pm

ORD

SEA

6h 37m1 stop

5:50 pm - 11:50 pm

SEA

ORD

4h 00mnonstop

$185Alaska Airlines

Fri, Jan 23 - Sun, Feb 1

3:58 pm - 9:47 pm

MLI

SEA

7h 49m1 stop

6:00 am - 3:27 pm

SEA

MLI

7h 27m1 stop

$265American Airlines

Tue, Jan 20 - Sat, Jan 24

Frontier flights from Illinois to Seattle

Our best Frontier deals on Illinois to Seattle flight tickets

Frontier

Jan 8

MDW12:41 pmChicago Midway

24h 40m

2 stops

SEA11:21 amSeattle/Tacoma Intl

Jan 15

SEA12:59 pmSeattle/Tacoma Intl

20h 48m

1 stop

MDW11:47 amChicago Midway

$184

Find similar

Frontier

Jan 8

ORD10:32 pmChicago O'Hare Intl

23h 15m

1 stop

SEA7:47 pmSeattle/Tacoma Intl

Jan 15

SEA12:19 pmSeattle/Tacoma Intl

7h 05m

1 stop

ORD9:24 pmChicago O'Hare Intl

$189

Find similar

Frontier

Jan 8

MDW12:41 pmChicago Midway

24h 40m

2 stops

SEA11:21 amSeattle/Tacoma Intl

Jan 11

SEA12:26 pmSeattle/Tacoma Intl

23h 39m

1 stop

MDW2:05 pmChicago Midway

$190

Find similar

American Airlines flights from Illinois to Seattle

Our best American Airlines deals on Illinois to Seattle flight tickets

American Airlines

Jan 11

ORD7:36 pmChicago O'Hare Intl

4h 44m

SEA10:20 pmSeattle/Tacoma Intl

Jan 14

SEA8:04 amSeattle/Tacoma Intl

4h 11m

ORD2:15 pmChicago O'Hare Intl

$181

Find similar

American Airlines

Jan 5

ORD7:25 amChicago O'Hare Intl

4h 37m

SEA10:02 amSeattle/Tacoma Intl

Jan 7

SEA8:04 amSeattle/Tacoma Intl

4h 11m

ORD2:15 pmChicago O'Hare Intl

$224

Find similar

American Airlines

Jan 20

MLI3:58 pmMoline Quad-City

7h 49m

1 stop

SEA9:47 pmSeattle/Tacoma Intl

Jan 24

SEA6:00 amSeattle/Tacoma Intl

7h 27m

1 stop

MLI3:27 pmMoline Quad-City

$265

Find similar

Fly from

Fly to

Route

Depart

Return

Price

ChicagoSeattle

MDW - SEA

MDWSEA

Chicago Midway

Mon 1/12

10:35 am-1:15 pm

Nonstop4h 40m

Seattle/Tacoma Intl

Sun 1/18

6:45 am-12:40 pm

Nonstop3h 55m

$177

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Thu 1/15

8:50 am-11:32 am

Nonstop4h 42m

Seattle/Tacoma Intl

Sun 1/18

10:58 am-5:03 pm

Nonstop4h 05m

$177

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Tue 1/6

1:09 pm-3:57 pm

Nonstop4h 48m

Seattle/Tacoma Intl

Tue 1/6

9:00 pm-5:02 am

1 stop6h 02m

$178

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Fri 1/23

2:06 pm-6:43 pm

1 stop6h 37m

Seattle/Tacoma Intl

Fri 1/30

8:30 am-2:38 pm

Nonstop4h 08m

$179

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Thu 1/8

3:35 pm-6:22 pm

Nonstop4h 47m

Seattle/Tacoma Intl

Thu 1/15

12:19 pm-9:24 pm

1 stop7h 05m

$180

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Sun 1/11

7:36 pm-10:20 pm

Nonstop4h 44m

Seattle/Tacoma Intl

Wed 1/14

8:04 am-2:15 pm

Nonstop4h 11m

$181

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Thu 1/8

3:44 pm-10:15 pm

1 stop8h 31m

Seattle/Tacoma Intl

Wed 1/14

5:50 pm-11:50 pm

Nonstop4h 00m

$182

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Thu 1/8

7:54 pm-10:43 pm

Nonstop4h 49m

Seattle/Tacoma Intl

Mon 1/12

12:35 pm-11:14 pm

1 stop8h 39m

$183

ChicagoSeattle

ORD - SEA

ORDSEA

Chicago O'Hare Intl

Fri 1/23

2:06 pm-6:43 pm

1 stop6h 37m

Seattle/Tacoma Intl

Sun 2/1

5:50 pm-11:50 pm

Nonstop4h 00m

$185

MolineSeattle

MLI - SEA

MLISEA

Moline Quad-City

Tue 1/20

3:58 pm-9:47 pm

1 stop7h 49m

Seattle/Tacoma Intl

Sat 1/24

6:00 am-3:27 pm

1 stop7h 27m

$265

Flights are sorted by cheapest round-trip flights first.

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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

Prices

Airlines

Other information

What is the cheapest month to fly to Seattle?

In general, February 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 $218. If you don’t want to visit Seattle in February, then you should wait until April to fly from Illinois, when ticket prices are also cheap, with an average price of $233.

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 $334. However, this price may fluctuate depending on the airline, the season, and holidays. On the other hand, Sunday 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 $445.

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 $322 when looking at flights departing in the evening. Flights to Seattle are more costly in the morning, with an average ticket price of $370. Departure times in the morning 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 $284 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 $245 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 8% 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	$138
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 $138. The best round-trip flight deal from Illinois to Seattle found on momondo in the last 72 hours is $257.

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?
As of December 2025, there are 8 operators available to choose from 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?
momondo data reveals that the most frequently booked plane model on the route from Illinois to Seattle is Boeing 737-800, representing 24.67% of all bookings. The subsequent popular models are Airbus A321neo at 14.62%, Boeing 737 MAX 8 at 11.87%, and Boeing 737 MAX 9 at 10.57%.

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 Airlines	PriceFrom $91	Free Cancellation	Rating 7.8 2,818 reviews	Search Hawaiian Airlines flights
Spirit Airlines	PriceFrom $105	Free Cancellation	Rating 6.3 8,174 reviews	Search Spirit Airlines flights
Delta	PriceFrom $120	Free Cancellation	Rating 7.9 8,009 reviews	Search Delta flights
Frontier	PriceFrom $142	Free Cancellation	Rating 5.8 3,084 reviews	Search Frontier flights
Alaska Airlines	PriceFrom $169	Free Cancellation	Rating 8.0 11,429 reviews	Search Alaska Airlines flights
American Airlines	PriceFrom $175	Free Cancellation	Rating 7.2 11,048 reviews	Search American Airlines flights
United Airlines	PriceFrom $177	Free Cancellation	Rating 7.4 9,095 reviews	Search United Airlines flights
Southwest	PriceFrom $189	Free Cancellation	Rating 7.9 4,252 reviews	Search Southwest flights

Tacoma

Leavenworth

SeaTac

Ocean Shores

Renton

Olympia

Lynnwood

Kent

Puyallup

Marysville

Redmond

Tukwila

Cle Elum

Federal Way

Lakewood

Fife

Westport

Kirkland

Centralia

Shoreline

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

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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Cheap flights from Illinois to Seattle from $68

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 1/7. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

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Big names and deals

Filter for what you want

Filter for what you want

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Find the cheapest flights from Illinois to Seattle

Cheap round-trip flights

Cheap one-way flights

Cheap last minute flights

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Frontier flights from Illinois to Seattle

Our best Frontier deals on Illinois to Seattle flight tickets

American Airlines flights from Illinois to Seattle

Our best American Airlines deals on Illinois to Seattle flight tickets

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Use the filters below to find and compare flights from Illinois to Seattle that are best for you.

See travel insights to Seattle from

How to get the cheapest flight ticket from Illinois to Seattle

What is the cheapest month to fly to Seattle?

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

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

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?

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 8% on your flight if you consider stops on a Illinois to Seattle flight.

What is the cheapest airline that flies from Illinois to Seattle/Tacoma Intl?

Frontier, American Airlines, and Southwest are the most popular carriers operating from Illinois to Seattle/Tacoma Intl

What airlines fly to Seattle?

How many flights depart from Illinois to Seattle on average per day?

41 flights are operational daily from Illinois to Seattle as of December 2025. The most popular departure time for this route is 8:00PM, with 39% of flights per day taking off at noon.

How many flights depart from Illinois to Seattle on average per week?

As of December 2025, there are 290 flights per week flying from Illinois to Seattle. The most common day of the week flights depart is Thu, with 18% of flights taking off on this day.

How long does it take to fly 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

Fastest flight time

Direct flights

Airports in Seattle

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

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?

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

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

Traveling to a place near Seattle?

Why use momondo?

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

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

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

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

An easier way to manage your Seattle 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.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

Find better results for your trip to the United States

Airports servicing Washington