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$82+ 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 5/26. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — ORD
maj 30 — juni 61
lør. 5/30
lør. 6/6
1 adult, Economy
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Cheap 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 april 30, 2026.

This CheapOair deal was found by Cheapflights users on 4/29. 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.
tor. 5/149:46 pm
PDX
-
STL
1 stop20h 37m
Frontier
ons. 5/206:51 pm
STL
-
PDX
1 stop17h 29m
Frontier
Deal found 4/29$216
This CheapOair deal was found by Cheapflights users on 4/26. 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.
søn. 5/109:46 pm
PDX
-
STL
1 stop20h 37m
Frontier
ons. 5/206:51 pm
STL
-
PDX
1 stop17h 29m
Frontier
Deal found 4/26$221
This CheapOair deal was found by Cheapflights users on 4/27. 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.
fre. 5/87:50 pm
SEA
-
ORD
1 stop22h 42m
Frontier
tir. 5/129:37 pm
ORD
-
SEA
1 stop14h 12m
Frontier
Deal found 4/27$236
This CheapOair deal was found by Cheapflights users on 4/29. 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.
lør. 5/2312:35 pm
PDX
-
STL
1 stop28h 48m
Frontier
lør. 5/306:30 pm
STL
-
PDX
1 stop17h 50m
Frontier
Deal found 4/29$236
This CheapOair deal was found by Cheapflights users on 4/27. 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.
søn. 5/1011:06 am
SEA
-
ORD
1 stop17h 33m
Frontier
ons. 5/139:37 pm
ORD
-
SEA
1 stop14h 12m
Frontier
Deal found 4/27$237
This CheapOair deal was found by Cheapflights users on 4/26. 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.
man. 6/87:50 pm
SEA
-
ORD
1 stop22h 53m
Frontier
lør. 6/209:48 pm
ORD
-
SEA
1 stop14h 00m
Frontier
Deal found 4/26$241
This CheapOair deal was found by Cheapflights users on 4/26. 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.
man. 5/117:50 pm
SEA
-
ORD
1 stop22h 42m
Frontier
fre. 5/158:56 pm
ORD
-
SEA
1 stop22h 41m
Frontier
Deal found 4/26$242
This Expedia deal was found by Cheapflights users on 4/25. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
man. 6/111:15 am
PDX
-
STL
1 stop6h 56m
Multiple Airlines
lør. 6/65:33 pm
STL
-
PDX
Nonstop4h 17m
Multiple Airlines
Deal found 4/25$244
This Trip.com deal was found by Cheapflights users on 4/27. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
man. 5/1811:06 am
SEA
-
ORD
1 stop17h 33m
Frontier
søn. 5/249:37 pm
ORD
-
SEA
1 stop14h 29m
Frontier
Deal found 4/27$248
This Frontier deal was found by Cheapflights users on 4/28. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
man. 6/158:12 pm
SEA
-
ORD
1 stop7h 20m
Frontier
fre. 6/199:48 pm
ORD
-
SEA
1 stop14h 00m
Frontier
Deal found 4/28$250
This Frontier deal was found by Cheapflights users on 4/29. 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 Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
man. 5/1811:06 am
SEA
-
ORD
1 stop17h 33m
Frontier
tir. 5/269:37 pm
ORD
-
SEA
1 stop14h 29m
Frontier
Deal found 4/29$251
This Booking.com deal was found by Cheapflights users on 4/27. 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 Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
ons. 5/67:50 pm
SEA
-
ORD
1 stop22h 42m
Frontier
fre. 5/89:37 pm
ORD
-
SEA
1 stop14h 12m
Frontier
Deal found 4/27$253

Find flight deals from Washington to Illinois

Keep the following information in mind while searching for Washington to Illinois flight deals. Data was last updated april 30, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$221
(CheapOair)

One-way from

$82
(Kiwi.com)

Popular in

December

Cheapest in

February

Average price

$317

Good round-trip deal

$363 or less

Good one-way deal

$184 or less
Provider with most accurate pricing for Seattle/Tacoma Intl-Chicago (CHI) flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Chicago (CHI) flights.
Search Deals
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. 1% potential price decrease ($6 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in April 2026
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

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 april 30, 2026.
Use the filters below to find and compare flights from Washington to Illinois that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

tor. 5/21

3:10 pm-11:21 pm

1 stop6h 11m

Lambert-St Louis

ons. 5/27

7:59 pm-11:44 pm

1 stop5h 45m

$303

PortlandChicago

PDX - ORD

PDXORD

Portland

lør. 6/6

2:12 pm-8:26 pm

Nonstop4h 14m

Chicago O'Hare Intl

lør. 6/13

7:56 pm-10:31 pm

Nonstop4h 35m

$305

PortlandSt. Louis

PDX - STL

PDXSTL

Portland

ons. 6/3

5:45 am-1:32 pm

1 stop5h 47m

Lambert-St Louis

lør. 6/6

5:00 pm-10:40 pm

1 stop7h 40m

$309

PortlandChicago

PDX - ORD

PDXORD

Portland

tor. 5/28

10:40 pm-4:45 am

Nonstop4h 05m

Chicago O'Hare Intl

ons. 6/3

5:00 am-9:47 am

1 stop6h 47m

$315

PortlandChicago

PDX - ORD

PDXORD

Portland

tor. 7/30

10:59 pm-5:00 am

Nonstop4h 01m

Chicago O'Hare Intl

ons. 8/5

7:20 am-9:45 am

Nonstop4h 25m

$316
Quickest round-trip

PortlandChicago

PDX - ORD

PDXORD

Portland

tor. 10/8

10:59 pm-4:51 am

Nonstop3h 52m

Chicago O'Hare Intl

tir. 10/13

7:10 am-9:30 am

Nonstop4h 20m

$316

PortlandChicago

PDX - ORD

PDXORD

Portland

tir. 6/30

11:40 pm-5:45 am

Nonstop4h 05m

Chicago O'Hare Intl

søn. 7/5

7:00 am-9:34 am

Nonstop4h 34m

$316

SpokaneChicago

GEG - MDW

GEGMDW

Spokane

tir. 6/2

5:10 am-2:10 pm

1 stop7h 00m

Chicago Midway

tir. 6/9

6:20 am-11:45 am

1 stop7h 25m

$317

SpokaneChicago

GEG - ORD

GEGORD

Spokane

tir. 6/2

1:41 pm-10:49 pm

1 stop7h 08m

Chicago O'Hare Intl

tir. 6/9

6:00 am-12:37 pm

1 stop8h 37m

$317

PortlandChicago

PDX - MDW

PDXMDW

Portland

tir. 7/21

11:30 pm-5:20 am

Nonstop3h 50m

Chicago Midway

tor. 7/30

5:00 am-9:55 am

1 stop6h 55m

$322

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/26

Showing 1-10 of 60 resultsSorted by cheapest first
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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

How far ahead should I book a flight from State of Washington to Illinois?

To ensure you get the cheapest price possible for a flight from State of Washington to Illinois, you should look to book at least 81 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

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

Currently, January is the cheapest month in which you can book a flight from State of Washington to Illinois (average of $47). Flying from State of Washington to Illinois in March is currently the most expensive (average of $512). 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 april 30, 2026.

When flying from State of Washington to Illinois, the time of day you fly usually plays a role in the price. Save by searching for a flight at noon, which can drop the price by up to 18% versus a flight in the evening.

What is the cheapest day to fly from State of Washington to Illinois?

Use this chart to determine the cheapest time to fly round-trip from Washington to Illinois. Price data was last updated on April 25, 2026.

Travelers seeking maximum savings on their State of Washington to Illinois flight should consider departing on Saturday afternoons when fares are most often at their lowest. Sunday evenings flights should be avoided if possible as fares are typically the most expensive at this time.

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 april 30, 2026.

The most flights from USWA to USIL are scheduled on a Wednesday (53 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (31 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 april 30, 2026.
Get a feel of what it's like to fly with Southwest,Alaska Airlines, andDelta 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.
Southwest
8.0
Very good
4,314 reviews

Crew

8.6

Overall

8.0

Food

7.0

Comfort

8.0

Boarding

8.1

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Southwest
8.0
Very good
4,314 reviews
Southwest
8.0
Very good
4,314 reviews

Crew

8.6

Overall

8.0

Food

7.0

Comfort

8.0

Boarding

8.1

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Alaska Airlines
7.9
Good
12,318 reviews
Southwest
8.0
Very good
4,314 reviews

Crew

8.6

Overall

8.0

Food

7.0

Comfort

8.0

Boarding

8.1

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
Delta
7.9
Good
8,464 reviews
Southwest
8.0
Very good
4,314 reviews

Crew

8.6

Overall

8.0

Food

7.0

Comfort

8.0

Boarding

8.1

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
United Airlines
7.4
Good
9,677 reviews
Southwest
8.0
Very good
4,314 reviews

Crew

8.6

Overall

8.0

Food

7.0

Comfort

8.0

Boarding

8.1

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.
American Airlines
7.1
Good
11,681 reviews
Southwest
8.0
Very good
4,314 reviews

Crew

8.6

Overall

8.0

Food

7.0

Comfort

8.0

Boarding

8.1

Entertainment

7.5

Reviews

1 / 20
2.0
Mediocre

Dominic,Mar 2026

MCO - SMF

I had to try and sleep on the floor of the Austin airport. I spent 12 hours there. The airline policies were so poor, that a near violent argument broke out between the people in front of me and the flight attendants - making for a super stressful situation at 30,000 feet. Garbage airline choice by Kayak Garbage idea to book a flight with a layover. Next time I will pay for a quality booking myself, and somehow force the company to reimburse it.

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 $305, Frontier can have you in Illinois from State of Washington in 4h 14m. The distance between State of Washington and Illinois is about 1733 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 $74 on Frontier. Other airlines that offer cheap prices include Delta from $84 and Southwest from $84 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, January is the cheapest month in which you can book a flight from State of Washington to Illinois (average of $47). Flying from State of Washington to Illinois in March is currently the most expensive (average of $512). 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

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Alternative routes for Washington to Illinois

See prices for flight routes from nearby airports that may be better suited for you.
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Top 7 airlines flying from Washington to Illinois

Discover the top 7 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 april 30, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$109Average$359FlexibilityNo cancel feeOn-timeN/A
Hawaiian AirlinesCheapest$118Average$249FlexibilityNo cancel feeOn-time85%
United AirlinesCheapest$164Average$412FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$170Average$414FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$177Average$350FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$177Average$405FlexibilityNo cancel feeOn-time71%
FrontierCheapest$193Average$308FlexibilityNo cancel feeOn-time62%

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