HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Illinois

$57+ Cheap flights from Washington to Illinois

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/15. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ORD
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Washington to Illinois with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheap flight deals from Washington to Illinois

Keep the following information in mind while searching for Washington to Illinois flight deals. Data was last updated September 11, 2025.

Round-trip from

$171
(Southwest)

One-way from

$57
(Southwest)

Popular in

December

Cheapest in

January

Average price

$263

Good round-trip deal

$256 or less

Good one-way deal

$153 or less
From Washington to Illinois
Search Deals
One-way flight from Washington to Illinois
Search Deals
Highest demand for flights based on searches. 4% potential increase in price ($14 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($8 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in September 2025
Search Deals
Price to beat on a round-trip flight from Washington to Illinois.
Search Deals
Price to beat on a one-way flight from Washington to Illinois.
Search Deals

Find flight deals from Washington to Illinois

Cheapest flights from Washington to Illinois
Explore the most affordable flight options available from Washington to Illinois. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 11, 2025.

This Southwest deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/249:35 amSEA - STL
2 stops7h 45mSouthwest
Tue 10/288:45 amSTL - SEA
1 stop9h 40mSouthwest
Deal found 9/10$171
This Kiwi.com deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 9/307:00 amSEA - STL
1 stop24h 06mFrontier
Mon 10/69:29 pmSTL - SEA
2 stops16h 38mFrontier
Deal found 9/9$172
This Kiwi.com deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 10/124:11 pmSEA - STL
2 stops14h 56mFrontier
Tue 10/147:52 pmSTL - SEA
1 stop18h 15mFrontier
Deal found 9/9$173
This Southwest deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/15:45 amSEA - STL
1 stop9h 15mSouthwest
Tue 11/42:25 pmSTL - SEA
2 stops10h 30mSouthwest
Deal found 9/10$174
This Kiwi.com deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 11/102:22 pmSEA - STL
1 stop16h 45mFrontier
Fri 11/147:45 pmSTL - SEA
1 stop18h 28mFrontier
Deal found 9/9$175
This Delta deal was found by Cheapflights users on 9/11. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 10/145:00 pmSEA - STL
1 stop5h 24mDelta
Thu 10/237:30 pmSTL - SEA
1 stop6h 29mDelta
Deal found 9/11$177
This Delta deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/83:37 pmGEG - ORD
1 stop6h 13mDelta
Wed 10/156:05 pmORD - GEG
1 stop7h 54mDelta
Deal found 9/10$177
This Delta deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/86:00 amSEA - STL
1 stop7h 31mDelta
Wed 11/125:34 pmSTL - SEA
1 stop8h 25mDelta
Deal found 9/9$178
This Delta deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/63:37 pmGEG - ORD
1 stop6h 13mDelta
Thu 10/97:37 amORD - GEG
1 stop9h 20mDelta
Deal found 9/9$178
This Delta deal was found by Cheapflights users on 9/9. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 11/81:35 pmSEA - STL
1 stop7h 32mDelta
Sat 11/156:50 amSTL - SEA
1 stop8h 06mDelta
Deal found 9/9$179
This United Airlines deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/311:20 amGEG - ORD
Nonstop3h 43mUnited Airlines
Tue 10/79:30 amORD - GEG
Nonstop4h 12mUnited Airlines
Deal found 9/10$179
This Kiwi.com deal was found by Cheapflights users on 9/10. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/17:00 amSEA - STL
1 stop24h 06mFrontier
Sun 10/510:39 amSTL - SEA
2 stops27h 02mFrontier
Deal found 9/10$180

Cheapflights Fare Finder

 
Customize your flight search to find flights from Washington 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, Cheapflights users made 2,558,603 searches. Data last updated September 11, 2025.
Use the filters below to find and compare flights from Washington to Illinois that are best for you.

Fly from

Washington

Fly to

Illinois

Route

Depart

Return

Price

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Wed 10/22

1:20 pm-12:10 am

2 stops8h 50m

Lambert-St Louis

Tue 10/28

3:00 pm-10:55 pm

1 stop9h 55m

$172

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Sat 11/1

5:45 am-5:00 pm

1 stop9h 15m

Lambert-St Louis

Tue 11/4

2:25 pm-10:55 pm

2 stops10h 30m

$174

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Thu 10/2

11:40 pm-8:37 am

1 stop6h 57m

Lambert-St Louis

Mon 10/6

5:31 pm-11:57 pm

1 stop8h 26m

$177

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Sat 10/25

6:00 am-3:31 pm

1 stop7h 31m

Lambert-St Louis

Sat 11/1

5:30 pm-10:22 pm

1 stop6h 52m

$177

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Sat 11/15

6:00 am-4:49 pm

1 stop8h 49m

Lambert-St Louis

Mon 11/17

7:47 pm-12:11 am

1 stop6h 24m

$177

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

Fri 11/7

1:30 pm-12:24 am

1 stop8h 54m

Lambert-St Louis

Tue 11/11

6:50 am-12:56 pm

1 stop8h 06m

$177

SpokaneChicago

GEG - ORD

GEGORD

Spokane

Tue 11/4

5:05 am-1:30 pm

1 stop6h 25m

Chicago O'Hare Intl

Tue 11/4

6:05 pm-10:48 pm

1 stop6h 43m

$177

SpokaneChicago

GEG - ORD

GEGORD

Spokane

Thu 10/23

5:05 am-1:30 pm

1 stop6h 25m

Chicago O'Hare Intl

Sat 10/25

8:57 am-1:05 pm

1 stop6h 08m

$183

SpokaneChicago

GEG - ORD

GEGORD

Spokane

Fri 10/31

1:15 pm-11:50 pm

1 stop8h 35m

Chicago O'Hare Intl

Sat 11/8

7:37 am-12:35 pm

1 stop6h 58m

$187

SpokaneChicago

GEG - ORD

GEGORD

Spokane

Tue 3/3

8:40 pm-5:04 am

1 stop6h 24m

Chicago O'Hare Intl

Wed 3/4

7:45 am-12:50 pm

1 stop7h 05m

$189

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/11

Showing 1-10 of 60 results
1
2
3
...
6

Best time to book a flight from Washington to Illinois

Have a flexible travel schedule? Discover the best time to fly to Illinois from Washington with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Washington to Illinois

What is the cheapest month to book a flight from State of Washington to Illinois?

Currently, August is the cheapest month in which you can book a flight from State of Washington to Illinois (average of $245). Flying from State of Washington to Illinois in March is currently the most expensive (average of $321). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from WA to IL?

Find hourly flight availability from Washington to Illinois. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 11, 2025.

When flying from State of Washington to Illinois, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Weekly flight availability from State of Washington to Illinois

Explore weekly flight availability from Washington to Illinois. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated September 11, 2025.

The most flights from USWA to USIL are scheduled on a Thursday (65 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (48 on average).

Reviews of airlines servicing Illinois

Get insights into the airlines that provide service to Illinois. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Illinois. Reviews last updated September 11, 2025.
Get a feel of what it's like to fly with Alaska Airlines, Southwest, and Delta from Washington to Illinois by reading reviews from past customers. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Alaska Airlines
8.0
Very good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Southwest
8.0
Very good
4,248 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
Delta
8.0
Very good
7,960 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
United Airlines
7.4
Good
8,937 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.
American Airlines
7.2
Good
10,000 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Comfort

7.8

Entertainment

7.0

Overall

8.0

Food

7.1

Crew

8.5

Boarding

8.1

Reviews

1 / 20
10.0
Excellent

Jonathan,Jul 2025

SEA - BOS

Fantastic Check-in with easy baggage drop. While it took a while to find out which was the gate, the boarding was a dream, the stewards were simply incredible and the flight fantastic.

Related info for your journey

Find useful and relevant information for your journey from Washington to Illinois. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

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

    For as low as $189, Southwest can have you in Illinois from State of Washington in 6h 24m. The distance between State of Washington and Illinois is about 1493 mi. This flight may include one or multiple stops.

  • What are the cheapest airlines to fly from State of Washington to Illinois one-way?

    One-way options have recently been found by users for as low as $69 on Southwest. Other airlines that offer cheap prices include United Airlines from $82 and Delta from $89 one-way.

  • Can I find deals for flights from Washington to Illinois that include hotel bookings?

    Yes. In addition to deals on Washington to Illinois flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Washington to Illinois?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Washington to Illinois.

  • Can I find deals for business class flights from Washington to Illinois?

    Yes. Cheapflights offers flight deals from Washington to Illinois by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from State of Washington to Illinois?

    Currently, August is the cheapest month in which you can book a flight from State of Washington to Illinois (average of $245). Flying from State of Washington to Illinois in March is currently the most expensive (average of $321). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Washington to Illinois

See prices for flight routes from nearby airports that may be better suited for you.
Los Angeles to John F Kennedy Intl flights
John F Kennedy Intl to Los Angeles flights
Dallas/Fort Worth to John F Kennedy Intl flights
John F Kennedy Intl to Miami flights
John F Kennedy Intl to Las Vegas flights
Dallas/Fort Worth to Las Vegas flights
Dallas/Fort Worth to LaGuardia flights
Dallas/Fort Worth to O'Hare Intl flights
San Francisco to John F Kennedy Intl flights
LaGuardia to Dallas/Fort Worth flights
Newark to Las Vegas flights
Newark to Fort Lauderdale flights
John F Kennedy Intl to O'Hare Intl flights
Seattle to Las Vegas flights
LaGuardia to O'Hare Intl flights
Newark to Miami flights
LaGuardia to Fort Lauderdale flights
Newark to O'Hare Intl flights
O'Hare Intl to John F Kennedy Intl flights
Los Angeles to Newark flights
John F Kennedy Intl to Dallas/Fort Worth flights
O'Hare Intl to LaGuardia flights
Los Angeles to Seattle flights
LaGuardia to Miami flights
John F Kennedy Intl to San Francisco flights
Dallas/Fort Worth to Newark flights
John F Kennedy Intl to Orlando flights
Newark to Dallas/Fort Worth flights
O'Hare Intl to Newark flights
San Francisco to Newark flights
O'Hare Intl to Dallas/Fort Worth flights
Newark to Los Angeles flights
Dallas/Fort Worth to Denver flights
O'Hare Intl to Las Vegas flights
Los Angeles to LaGuardia flights
Dallas/Fort Worth to Seattle flights
Atlanta to John F Kennedy Intl flights
Los Angeles to O'Hare Intl flights
Seattle to Los Angeles flights
John F Kennedy Intl to Fort Lauderdale flights
Dulles Intl to Dallas/Fort Worth flights
Newark to Orlando flights
Seattle to Dallas/Fort Worth flights
John F Kennedy Intl to Atlanta flights
Los Angeles to Dallas/Fort Worth flights
Los Angeles to Las Vegas flights
Los Angeles to San Francisco flights
LaGuardia to Denver flights
Fort Lauderdale to LaGuardia flights
Los Angeles to Honolulu flights

Top 8 airlines flying from Washington to Illinois

Discover the top 8 airlines that operate flights from Washington to Illinois. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated September 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$107Average$189FlexibilityNo cancel feeOn-time65%
DeltaCheapest$118Average$336FlexibilityNo cancel feeOn-timeN/A
Hawaiian AirlinesCheapest$121Average$286FlexibilityNo cancel feeOn-time85%
FrontierCheapest$137Average$280FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$169Average$443FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$170Average$466FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$170Average$387FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$172Average$427FlexibilityNo cancel feeOn-time71%

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.