HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Illinois

$84+ 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 9/23. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ORD
ago. 5 — ago. 121
mar. 8/5
mar. 8/12
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 julio 31, 2025.

Round-trip from

$174
(United Airlines)

One-way from

$84
(United Airlines)

Popular in

December

Cheapest in

January

Average price

$333

Good round-trip deal

$241 or less

Good one-way deal

$165 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 ($13 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 July 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 julio 31, 2025.

This United Airlines deal was found by Cheapflights users on 7/30. 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.
mié. 9/37:00 amSEA - STL
1 stop6h 44mUnited Airlines
vie. 9/55:49 pmSTL - SEA
1 stop7h 10mUnited Airlines
Deal found 7/30$174
This Kiwi.com deal was found by Cheapflights users on 7/30. 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.
vie. 9/1212:59 amSEA - ORD
Nonstop4h 04mHawaiian Airlines
sáb. 9/202:07 pmORD - SEA
1 stop6h 38mHawaiian Airlines
Deal found 7/30$175
This Delta deal was found by Cheapflights users on 7/29. 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.
mar. 8/265:30 amSEA - STL
1 stop6h 00mDelta
mar. 9/27:35 amSTL - SEA
1 stop9h 08mDelta
Deal found 7/29$177
This Southwest deal was found by Cheapflights users on 7/31. 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.
sáb. 8/3011:10 pmSEA - MDW
Nonstop4h 05mSouthwest
dom. 8/318:20 pmMDW - SEA
Nonstop4h 30mSouthwest
Deal found 7/31$179
This Alaska Airlines deal was found by Cheapflights users on 7/29. 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 Alaska Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 8/2512:59 amSEA - ORD
Nonstop4h 04mAlaska Airlines
mar. 8/2610:00 amORD - SEA
Nonstop4h 34mAlaska Airlines
Deal found 7/29$183
This Delta deal was found by Cheapflights users on 7/31. 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.
mar. 8/265:50 pmSEA - ORD
Nonstop4h 01mDelta
dom. 8/317:15 amORD - SEA
Nonstop4h 30mDelta
Deal found 7/31$184
This CheapOair deal was found by Cheapflights users on 7/29. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 8/75:30 pmSEA - ORD
1 stop10h 33mSpirit Airlines
mar. 8/127:08 amORD - SEA
1 stop11h 17mSpirit Airlines
Deal found 7/29$188
This American Airlines deal was found by Cheapflights users on 7/30. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
jue. 9/253:00 pmSEA - STL
1 stop6h 48mAmerican Airlines
lun. 10/65:11 amSTL - SEA
1 stop9h 34mAmerican Airlines
Deal found 7/30$189
This Hawaiian Airlines deal was found by Cheapflights users on 7/29. 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 Hawaiian Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 9/61:40 pmGEG - ORD
1 stop8h 23mHawaiian Airlines
sáb. 9/135:45 pmORD - GEG
1 stop8h 34mHawaiian Airlines
Deal found 7/29$194
This United Airlines deal was found by Cheapflights users on 7/31. 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.
mié. 9/38:00 amSEA - ORD
1 stop8h 25mUnited Airlines
sáb. 9/67:10 amORD - SEA
Nonstop4h 33mUnited Airlines
Deal found 7/31$195
This Delta deal was found by Cheapflights users on 7/29. 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.
sáb. 9/131:18 pmGEG - ORD
1 stop8h 41mDelta
mar. 9/237:55 amORD - GEG
1 stop6h 00mDelta
Deal found 7/29$195
This American Airlines deal was found by Cheapflights users on 7/30. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/51:14 pmGEG - ORD
Nonstop3h 58mAmerican Airlines
sáb. 11/1510:30 amORD - GEG
Nonstop4h 02mAmerican Airlines
Deal found 7/30$197

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 julio 31, 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

mié. 9/3

7:00 am-3:44 pm

1 stop6h 44m

Lambert-St Louis

vie. 9/5

5:49 pm-10:59 pm

1 stop7h 10m

$174

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

vie. 9/12

12:59 am-7:03 am

Nonstop4h 04m

Chicago O'Hare Intl

sáb. 9/20

2:07 pm-6:45 pm

1 stop6h 38m

$175

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

mar. 8/26

5:30 am-1:30 pm

1 stop6h 00m

Lambert-St Louis

mar. 9/2

7:35 am-2:43 pm

1 stop9h 08m

$177

SeattleChicago

SEA - MDW

SEAMDW

Seattle/Tacoma Intl

sáb. 8/30

11:10 pm-5:15 am

Nonstop4h 05m

Chicago Midway

dom. 8/31

8:20 pm-10:50 pm

Nonstop4h 30m

$179

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

lun. 8/25

12:59 am-7:03 am

Nonstop4h 04m

Chicago O'Hare Intl

mar. 8/26

10:00 am-12:34 pm

Nonstop4h 34m

$183

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

sáb. 8/30

5:50 pm-11:51 pm

Nonstop4h 01m

Chicago O'Hare Intl

sáb. 9/6

7:15 am-9:45 am

Nonstop4h 30m

$185

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

jue. 8/7

5:30 pm-6:03 am

1 stop10h 33m

Chicago O'Hare Intl

mar. 8/12

7:08 am-4:25 pm

1 stop11h 17m

$188

SeattleSt. Louis

SEA - STL

SEASTL

Seattle/Tacoma Intl

jue. 9/25

3:00 pm-11:48 pm

1 stop6h 48m

Lambert-St Louis

lun. 10/6

5:11 am-12:45 pm

1 stop9h 34m

$189

SpokaneChicago

GEG - ORD

GEGORD

Spokane

sáb. 9/6

1:40 pm-12:03 am

1 stop8h 23m

Chicago O'Hare Intl

sáb. 9/13

5:45 pm-12:19 am

1 stop8h 34m

$194

SeattleChicago

SEA - ORD

SEAORD

Seattle/Tacoma Intl

mié. 9/3

8:00 am-6:25 pm

1 stop8h 25m

Chicago O'Hare Intl

sáb. 9/6

7:10 am-9:43 am

Nonstop4h 33m

$195

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/29

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 julio 31, 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 julio 31, 2025.

The most flights from USWA to USIL are scheduled on a Thursday (81 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (39 on average).

How much does it cost to fly round-trip from State of Washington to Illinois?

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 julio 31, 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

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

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

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

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
4,246 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

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
7,981 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

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.
Hawaiian Airlines
7.8
Good
2,611 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

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
8,900 reviews
Alaska Airlines
8.0
Very good
10,000 reviews

Entertainment

7.1

Comfort

7.8

Boarding

8.1

Food

7.1

Overall

8.0

Crew

8.5

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.

  • 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 $84 on United Airlines. Other airlines that offer cheap prices include Delta from $89 and Hawaiian Airlines from $90 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.
Newark to Fort Lauderdale flights
Dallas/Fort Worth to LaGuardia flights
John F Kennedy Intl to Los Angeles flights
Los Angeles to John F Kennedy Intl flights
John F Kennedy Intl to Las Vegas flights
Los Angeles to Newark flights
Dallas/Fort Worth to O'Hare Intl flights
Los Angeles to Las Vegas flights
Newark to O'Hare Intl flights
Newark to Los Angeles flights
LaGuardia to O'Hare Intl flights
LaGuardia to Fort Lauderdale flights
John F Kennedy Intl to Orlando flights
John F Kennedy Intl to Miami flights
Dallas/Fort Worth to Seattle flights
Dallas/Fort Worth to Las Vegas flights
San Francisco to John F Kennedy Intl flights
Newark to Orlando flights
John F Kennedy Intl to O'Hare Intl flights
O'Hare Intl to LaGuardia flights
John F Kennedy Intl to Seattle flights
John F Kennedy Intl to San Francisco flights
Newark to Miami flights
O'Hare Intl to John F Kennedy Intl flights
O'Hare Intl to Newark flights
Los Angeles to Honolulu flights
LaGuardia to Miami flights
Los Angeles to Seattle flights
LaGuardia to Dallas/Fort Worth flights
Atlanta to John F Kennedy Intl flights
Newark to Seattle flights
Fort Lauderdale to Newark flights
O'Hare Intl to Dallas/Fort Worth flights
Los Angeles to O'Hare Intl flights
Dallas/Fort Worth to Los Angeles flights
Newark to San Francisco flights
Los Angeles to Dallas/Fort Worth flights
Dallas/Fort Worth to Newark flights
John F Kennedy Intl to Fort Lauderdale flights
John F Kennedy Intl to Atlanta flights
LaGuardia to Orlando flights
Dallas/Fort Worth to Denver flights
Los Angeles to LaGuardia flights
San Francisco to Newark flights
San Francisco to Seattle flights
Atlanta to LaGuardia flights
Dallas/Fort Worth to John F Kennedy Intl flights
LaGuardia to Atlanta flights
Ontario to San Francisco flights
Hobby to LaGuardia 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 julio 31, 2025.
AirlineCheapestAverageFlexibilityOn-time
Spirit AirlinesCheapest$93Average$161FlexibilityNo cancel feeOn-time65%
DeltaCheapest$117Average$368FlexibilityNo cancel feeOn-timeN/A
Hawaiian AirlinesCheapest$121Average$289FlexibilityNo cancel feeOn-time85%
FrontierCheapest$137Average$276FlexibilityNo cancel feeOn-time62%
United AirlinesCheapest$160Average$461FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$168Average$476FlexibilityNo cancel feeOn-time75%
American AirlinesCheapest$169Average$459FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$179Average$386FlexibilityNo cancel feeOn-time63%

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.