What is the cheapest airline that flies from Washington to Illinois?

Frontier, Alaska Airlines, and American Airlines are the most popular carriers operating from Washington to Illinois

What airlines fly to Illinois?

American Airlines, Alaska Airlines and United Airlines are the top three most popular airlines that fly to Illinois from State of Washington according to our data. American Airlines is the first choice among our users, with 31% of people opting to fly with this airline when traveling to Illinois. Keep in mind that there are 7 different airlines that fly to Illinois on a routine basis, so you have a few additional options to choose from.

How many flights depart from State of Washington to Illinois on average per day?

77 flights are operational daily from State of Washington to Illinois as of May 2026. The most popular departure time for this route is 1:00PM, with 53% of flights per day taking off at noon.

How many flights depart from State of Washington to Illinois on average per week?

As of May 2026, 543 flights take off from State of Washington and land in Illinois each week. The most common flight departure day for this route is Tue, with 17% of weekly flights taking off on this day.

How long is the flight from State of Washington to Illinois?

The flight from State of Washington to Illinois depends on which airports you’re departing and arriving from and whether or not you have a layover. If you fly from Spokane (a popular airport in State of Washington) to Chicago O'Hare Intl Airport (the most popular airport in Illinois), then the flight time is 3h 35m on average. If you fly from Seattle (another popular airport in State of Washington) to Chicago O'Hare Intl Airport, then the average flight time is 3h 57m.

When did momondo last update prices for flights from Washington to Illinois?

Prices for flights from Washington to Illinois are refreshed on a daily basis.

How many operators does momondo search for flights from Washington to Illinois?

The number of operators available for flights from Washington to Illinois is 7 as of May 2026.

How old do you have to be to fly from Washington to Illinois?

The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Washington to Illinois.

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

The required travel and health documents for your Illinois 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 Illinois. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

$79 Cheap Flights from Washington to Illinois in 2026

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Find the cheapest flights from Washington to Illinois

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

5:46 pm - 7:23 pm

PDX

STL

23h 37m

1 stop

9:21 pm - 10:20 am

STL

PDX

14h 59m

1 stop

$240Frontier

Tue, May 26 - Thu, May 28

12:26 pm - 6:53 pm

PDX

STL

28h 27m

1 stop

7:46 pm - 7:47 pm

STL

PDX

26h 01m

1 stop

$241Frontier

Thu, Jun 11 - Wed, Jun 17

12:46 pm - 11:59 pm

GEG

ORD

9h 13m

1 stop

9:00 am - 9:45 pm

ORD

GEG

14h 45m

1 stop

$277Alaska Airlines

Wed, May 27 - Wed, Jun 3

12:46 pm - 10:59 pm

GEG

ORD

8h 13m

1 stop

2:10 pm - 9:45 pm

ORD

GEG

9h 35m

1 stop

$286Alaska Airlines

Sat, May 30 - Tue, Jun 2

2:08 pm - 8:07 pm

GEG

ORD

3h 59mnonstop

11:30 am - 1:24 pm

ORD

GEG

3h 54mnonstop

$297American Airlines

Wed, May 27 - Wed, Jun 3

2:26 pm - 11:50 pm

SEA

STL

7h 24m

1 stop

4:40 pm - 9:11 pm

STL

SEA

6h 31m

1 stop

$307United Airlines

Thu, Aug 27 - Mon, Aug 31

3:40 pm - 11:57 pm

SEA

STL

6h 17m

1 stop

7:23 pm - 1:13 am

STL

SEA

7h 50m

1 stop

$308United Airlines

Sat, May 23 - Sun, May 24

11:12 pm - 8:43 am

PDX

MDW

7h 31m

1 stop

1:59 pm - 8:11 pm

MDW

PDX

8h 12m

1 stop

$325Delta

Sun, May 24 - Fri, May 29

10:40 pm - 10:00 am

GEG

MDW

9h 20m

1 stop

9:54 am - 1:18 pm

MDW

GEG

5h 24m

1 stop

$333Delta

Mon, Jun 1 - Tue, Jun 9

3:05 pm - 12:35 am

SEA

BMI

7h 30m

1 stop

6:02 pm - 12:41 am

BMI

SEA

8h 39m

1 stop

$343American Airlines

Tue, Jun 9 - Tue, Jun 30

American Airlines flights from State of Washington to Illinois

Our best American Airlines deals on State of Washington to Illinois flight tickets

American Airlines

May 27

GEG2:08 pmSpokane

3h 59m

ORD8:07 pmChicago O'Hare Intl

Jun 3

ORD11:30 amChicago O'Hare Intl

3h 54m

GEG1:24 pmSpokane

$297

American Airlines

May 24

PDX10:59 pmPortland

4h 03m

ORD5:02 amChicago O'Hare Intl

Jun 2

ORD7:20 pmChicago O'Hare Intl

4h 31m

PDX9:51 pmPortland

$306

American Airlines

May 27

GEG12:51 pmSpokane

8h 46m

1 stop

ORD11:37 pmChicago O'Hare Intl

Jun 3

ORD11:30 amChicago O'Hare Intl

3h 54m

GEG1:24 pmSpokane

$307

Frontier flights from State of Washington to Illinois

Our best Frontier deals on State of Washington to Illinois flight tickets

Frontier

May 26

PDX5:46 pmPortland

23h 37m

1 stop

STL7:23 pmLambert-St Louis

May 28

STL9:21 pmLambert-St Louis

14h 59m

1 stop

PDX10:20 amPortland

$240

Frontier

Jun 11

PDX12:26 pmPortland

28h 27m

1 stop

STL6:53 pmLambert-St Louis

Jun 17

STL7:46 pmLambert-St Louis

26h 01m

1 stop

PDX7:47 pmPortland

$241

Frontier

Jul 10

SEA8:12 pmSeattle/Tacoma Intl

7h 16m

1 stop

ORD5:28 amChicago O'Hare Intl

Jul 18

ORD9:57 pmChicago O'Hare Intl

13h 52m

1 stop

SEA9:49 amSeattle/Tacoma Intl

$245

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Tue 5/26

5:46 pm-7:23 pm

1 stop23h 37m

Lambert-St Louis

Thu 5/28

9:21 pm-10:20 am

1 stop14h 59m

$240

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

Thu 6/11

12:26 pm-6:53 pm

1 stop28h 27m

Lambert-St Louis

Wed 6/17

7:46 pm-7:47 pm

1 stop26h 01m

$241

SpokaneChicago

GEG - ORD

GEGORD

Spokane

Wed 5/27

12:46 pm-11:59 pm

1 stop9h 13m

Chicago O'Hare Intl

Wed 6/3

9:00 am-9:45 pm

1 stop14h 45m

$277

SpokaneChicago

GEG - ORD

GEGORD

Spokane

Sat 5/30

12:46 pm-10:59 pm

1 stop8h 13m

Chicago O'Hare Intl

Tue 6/2

2:10 pm-9:45 pm

1 stop9h 35m

$286

Quickest round-trip

SpokaneChicago

GEG - ORD

GEGORD

Spokane

Wed 5/27

2:08 pm-8:07 pm

Nonstop3h 59m

Chicago O'Hare Intl

Wed 6/3

11:30 am-1:24 pm

Nonstop3h 54m

$297

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 8/27

2:26 pm-11:50 pm

1 stop7h 24m

Lambert-St Louis

Mon 8/31

4:40 pm-9:11 pm

1 stop6h 31m

$307

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Sat 5/23

3:40 pm-11:57 pm

1 stop6h 17m

Lambert-St Louis

Sun 5/24

7:23 pm-1:13 am

1 stop7h 50m

$308

PortlandChicago

PDX - MDW

PDXMDW

Portland

Sun 5/24

11:12 pm-8:43 am

1 stop7h 31m

Chicago Midway

Fri 5/29

1:59 pm-8:11 pm

1 stop8h 12m

$325

SpokaneChicago

GEG - MDW

GEGMDW

Spokane

Mon 6/1

10:40 pm-10:00 am

1 stop9h 20m

Chicago Midway

Tue 6/9

9:54 am-1:18 pm

1 stop5h 24m

$333

SeattleBloomington

SEA - BMI

SEABMI

Seattle/Tacoma Intl

Tue 6/9

3:05 pm-12:35 am

1 stop7h 30m

Bloomington-Normal

Tue 6/30

6:02 pm-12:41 am

1 stop8h 39m

$343

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

How to get the cheapest flight ticket from State of Washington 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

Prices

Airlines

Other information

What is the cheapest month to fly to Illinois?

The cheapest month to fly to Illinois from State of Washington is in January. Flight prices, which tend to average around $47, 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 $93.

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

The cheapest day to depart from State of Washington to Illinois is on a Wednesday when prices can be found for as low as $402. Flights from State of Washington to Illinois on a Monday will generally be more expensive and average around $490. 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 State of Washington to Illinois during this time can be as low as $316. Flights in the morning are often more expensive with an average ticket price of $443.

What is the cheapest Washington to Illinois flight route?

Fly from Seattle/Tacoma Intl to Chicago O'Hare Intl for the best Washington - Illinois flight prices

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

You are more likely to see cheaper flights to Illinois from State of Washington 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 State of Washington for as low as $258 on momondo.

Can stopping save me money on State of Washington to Illinois flights?

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

Cheap State of Washington to Illinois flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from State of Washington to Illinois

Best Price Found	$196
Fastest flight time	3h 30m
Direct flights	Every day
Airports in Illinois	98 airports

The best one-way flight to Illinois from State of Washington in the past 72 hours is $196. The best round-trip flight deal from State of Washington to Illinois found on momondo in the last 72 hours is $362.

The fastest flight from State of Washington to Illinois takes 3h 30m

Direct flights go from State of Washington to Illinois every day.

There are 98 airports in Illinois. From State of Washington 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 Washington to Illinois

When did momondo last update prices for flights from Washington to Illinois?
Prices for flights from Washington to Illinois are refreshed on a daily basis.
How many operators does momondo search for flights from Washington to Illinois?
The number of operators available for flights from Washington to Illinois is 7 as of May 2026.
How old do you have to be to fly from Washington to Illinois?
The minimum age a child must be to fly alone is five but airlines that offer an unaccompanied minor (UNMR) service will have their own age restrictions, including rules around flight length, timings, and stopovers. We always recommend checking with the individual airline you are booking with to travel from Washington to Illinois.
What documentation or ID do you need to fly to Illinois?
The required travel and health documents for your Illinois 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 Illinois. 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 State of Washington to Illinois?
momondo data reveals that the most frequently booked plane model on the route from State of Washington to Illinois is Boeing 737-800, representing 20.58% of all bookings. The subsequent popular models are Boeing 737-900 at 14.74%, Airbus A321neo at 13.91%, and Boeing 737 MAX 9 at 12.77%.

Best airlines flying from State of Washington to Illinois

Compare and see reviews for airlines that fly from State of Washington to Illinois with momondo

Airline	Rating	Free Cancellation	Price
Delta	PriceFrom $108	Free Cancellation	Rating 7.9 8,462 reviews	Search Delta flights
Hawaiian Airlines	PriceFrom $121	Free Cancellation	Rating 7.8 2,837 reviews	Search Hawaiian Airlines flights
United Airlines	PriceFrom $164	Free Cancellation	Rating 7.4 9,684 reviews	Search United Airlines flights
Alaska Airlines	PriceFrom $170	Free Cancellation	Rating 7.9 12,330 reviews	Search Alaska Airlines flights
Southwest	PriceFrom $177	Free Cancellation	Rating 7.9 4,305 reviews	Search Southwest flights
American Airlines	PriceFrom $177	Free Cancellation	Rating 7.1 11,675 reviews	Search American Airlines flights
Frontier	PriceFrom $193	Free Cancellation	Rating 5.6 2,965 reviews	Search Frontier flights

Why use momondo?

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

It is quick and easy to find Washington to Illinois flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to Illinois that suits you.

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

momondo does allow users to show only those flights to Illinois from Washington which offer a flexible booking policy as well as other useful filters and features.

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

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Illinois from Washington.

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

If you are simply researching potential flights to Illinois, momondo offers a useful price alert feature which will track prices for flights to Illinois from Washington and alert you when they change.

An easier way to manage your Illinois trip

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Cheap flights from Washington to Illinois from $79

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Washington to Illinois departing on 6/9. 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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American Airlines flights from State of Washington to Illinois

Our best American Airlines deals on State of Washington to Illinois flight tickets

Frontier flights from State of Washington to Illinois

Our best Frontier deals on State of Washington to Illinois flight tickets

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How to get the cheapest flight ticket from State of Washington to Illinois

What is the cheapest month to fly to Illinois?

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

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

What is the cheapest Washington to Illinois flight route?

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

Can stopping save me money on State of Washington to Illinois flights?

What is the cheapest airline that flies from Washington to Illinois?

What airlines fly to Illinois?

How many flights depart from State of Washington to Illinois on average per day?

How many flights depart from State of Washington to Illinois on average per week?

How long is the flight from State of Washington to Illinois?

Cheap State of Washington to Illinois flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from State of Washington to Illinois

Best Price Found

Fastest flight time

Direct flights

Airports in Illinois

Frequently asked questions about flying from Washington to Illinois

Best airlines flying from State of Washington to Illinois

Compare and see reviews for airlines that fly from State of Washington to Illinois with momondo

Why use momondo?

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.

Get notified when prices go down

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

Find better results for your trip to Illinois

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