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$100+ Cheap flights from St. Louis (STL) to Washington

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 6/2. Fares are subject to change and may not be available on all flights or dates of travel.
STL — SEA
Jun 9 — Jun 161
Tue 6/9
Tue 6/16
1 adult, Economy
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Cheap flight deals from St. Louis to Washington

Cheapest flights from St. Louis to Washington
Explore the most affordable flight options available from St. Louis to Washington. Find the lowest fares from popular airlines and budget airlines, with prices last updated on May 10, 2026.

This Mytrip deal was found by Cheapflights users on 5/6. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 6/59:06 pm
STL
-
SEA
1 stop15h 30m
Frontier
Wed 6/108:12 pm
SEA
-
STL
1 stop15h 54m
Frontier
Deal found 5/6$239
This Kiwi.com deal was found by Cheapflights users on 5/5. 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 6/28:08 pm
STL
-
SEA
2 stops48h 57m
Frontier
Tue 6/97:41 pm
SEA
-
STL
1 stop21h 42m
Frontier
Deal found 5/5$242
This Kiwi.com deal was found by Cheapflights users on 5/5. 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 6/248:08 pm
STL
-
SEA
1 stop15h 40m
Frontier
Mon 7/137:41 pm
SEA
-
STL
1 stop21h 42m
Frontier
Deal found 5/5$246
This CheapOair deal was found by Cheapflights users on 5/6. 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.
Thu 5/288:08 pm
STL
-
SEA
1 stop15h 58m
Frontier
Fri 5/298:20 pm
SEA
-
STL
1 stop19h 14m
Frontier
Deal found 5/6$250
This Trip.com deal was found by Cheapflights users on 5/9. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/18:08 pm
STL
-
SEA
1 stop15h 58m
Frontier
Mon 6/87:50 pm
SEA
-
STL
1 stop21h 33m
Frontier
Deal found 5/9$251
This Mytrip deal was found by Cheapflights users on 5/7. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 6/18:08 pm
STL
-
SEA
1 stop15h 58m
Frontier
Sat 6/67:50 pm
SEA
-
STL
1 stop21h 33m
Frontier
Deal found 5/7$254
This Mytrip deal was found by Cheapflights users on 5/6. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 7/198:08 pm
STL
-
SEA
1 stop15h 41m
Frontier
Mon 8/107:41 pm
SEA
-
STL
1 stop21h 42m
Frontier
Deal found 5/6$255
This Trip.com deal was found by Cheapflights users on 5/7. 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.
Fri 5/298:08 pm
STL
-
SEA
1 stop15h 58m
Frontier
Wed 6/37:50 pm
SEA
-
STL
1 stop21h 33m
Frontier
Deal found 5/7$256
This Trip.com deal was found by Cheapflights users on 5/9. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/28:08 pm
STL
-
SEA
1 stop15h 58m
Frontier
Thu 6/118:12 pm
SEA
-
STL
1 stop15h 54m
Frontier
Deal found 5/9$257
This Trip.com deal was found by Cheapflights users on 5/8. 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.
Wed 6/108:08 pm
STL
-
SEA
1 stop15h 40m
Frontier
Fri 6/127:41 pm
SEA
-
STL
1 stop21h 12m
Frontier
Deal found 5/8$258
This Kiwi.com deal was found by Cheapflights users on 5/5. 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 6/248:08 pm
STL
-
SEA
1 stop15h 40m
Frontier
Tue 7/143:34 pm
SEA
-
STL
2 stops15h 23m
Frontier
Deal found 5/5$259
This Mytrip deal was found by Cheapflights users on 5/6. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 5/276:51 pm
STL
-
PDX
1 stop17h 14m
Frontier
Thu 5/2812:35 pm
PDX
-
STL
1 stop28h 48m
Frontier
Deal found 5/6$275

Find flight deals from St. Louis to Washington

Keep the following information in mind while searching for St. Louis to Washington flight deals. Data was last updated May 10, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$239
(Mytrip)

One-way from

$100
(Kiwi.com)

Popular in

July

Cheapest in

February

Average price

$388

Good round-trip deal

$452 or less

Good one-way deal

$264 or less
Provider with most accurate pricing for Lambert-St Louis-Seattle/Tacoma Intl flight deals.
Search Deals
Provider most trusted by Cheapflights users for Lambert-St Louis-Seattle/Tacoma Intl flights.
Search Deals
From Lambert-St Louis to Washington
Search Deals
One-way flight from Lambert-St Louis to Washington
Search Deals
Highest demand for flights based on searches. 15% potential increase in price ($60 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($9 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in May 2026
Search Deals
Price to beat on a round-trip flight from Lambert-St Louis to Washington.
Search Deals
Price to beat on a one-way flight from Lambert-St Louis to Washington.
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from St. Louis to Washington 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 May 10, 2026.
Use the filters below to find and compare flights from St. Louis to Washington that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Tue 8/18

5:10 am-10:01 am

1 stop6h 51m

Seattle/Tacoma Intl

Tue 8/25

8:40 am-4:34 pm

1 stop5h 54m

$279

St. LouisPortland

STL - PDX

STLPDX

Lambert-St Louis

Wed 5/27

7:59 pm-11:44 pm

1 stop5h 45m

Portland

Mon 6/1

11:12 pm-9:29 am

1 stop8h 17m

$309

St. LouisPortland

STL - PDX

STLPDX

Lambert-St Louis

Fri 7/10

6:30 pm-11:55 pm

1 stop7h 25m

Portland

Tue 7/14

12:35 pm-11:30 pm

2 stops8h 55m

$324

St. LouisPortland

STL - PDX

STLPDX

Lambert-St Louis

Mon 6/29

5:36 pm-11:18 pm

1 stop7h 42m

Portland

Sat 7/11

12:33 am-8:46 am

1 stop6h 13m

$344

St. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Tue 6/2

6:35 am-10:15 am

1 stop5h 40m

Spokane

Tue 6/9

1:35 pm-11:45 pm

1 stop8h 10m

$357

St. LouisSeattle

STL - SEA

STLSEA

Lambert-St Louis

Thu 10/8

4:40 pm-7:10 pm

Nonstop4h 30m

Seattle/Tacoma Intl

Wed 10/14

6:00 pm-11:59 pm

Nonstop3h 59m

$367

St. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Wed 7/8

6:21 am-11:39 am

1 stop7h 18m

Spokane

Tue 7/21

5:10 pm-12:41 am

1 stop5h 31m

$373
Quickest round-trip

St. LouisPortland

STL - PDX

STLPDX

Lambert-St Louis

Thu 5/28

5:33 pm-7:50 pm

Nonstop4h 17m

Portland

Wed 6/3

10:37 am-4:37 pm

Nonstop4h 00m

$377

St. LouisSpokane

STL - GEG

STLGEG

Lambert-St Louis

Sat 10/3

6:30 am-1:07 pm

1 stop8h 37m

Spokane

Thu 10/8

10:45 pm-8:12 am

1 stop7h 27m

$377

St. LouisPortland

STL - PDX

STLPDX

Lambert-St Louis

Sat 6/6

5:29 pm-10:29 pm

1 stop7h 00m

Portland

Sat 6/13

11:40 pm-8:39 am

1 stop6h 59m

$379

Flights are sorted by cheapest round-trip flights first.

Deals found on 5/9

Showing 1-10 of 60 resultsSorted by cheapest first
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Best time to book a flight from St. Louis to Washington

Have a flexible travel schedule? Discover the best time to fly to Washington from St. Louis 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 St. Louis to Washington

How far ahead should I book a flight from St. Louis to State of Washington?

To ensure you get the cheapest price possible for a flight from St. Louis to State of Washington, you should look to book at least 65 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 St. Louis to State of Washington?

Currently, March is the cheapest month in which you can book a flight from St. Louis to State of Washington (average of $80). Flying from St. Louis to State of Washington in August is currently the most expensive (average of $169). 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 STL to WA?

Find hourly flight availability from St. Louis to Washington. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated May 10, 2026.

Unlike in the morning, when flights are generally more expensive, you can save up to 17% on flights from St. Louis to State of Washington by exploring options for tickets in the afternoon.

What is the cheapest day to fly from St. Louis to State of Washington?

Use this chart to determine the cheapest time to fly round-trip from St. Louis to Washington. Price data was last updated on May 2, 2026.

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

How much does it cost to fly round-trip from St. Louis to State of Washington?

Reviews of airlines servicing Washington

Get insights into the airlines that provide service to Washington. 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 Washington. Reviews last updated May 10, 2026.
Read through reviews of airlines operating flights from St. Louis to Washington, such as Alaska Airlines,Southwest, andDelta. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
7.9
Good
12,353 reviews

Entertainment

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Food

7.0

Overall

7.9

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well
Alaska Airlines
7.9
Good
12,353 reviews
Alaska Airlines
7.9
Good
12,353 reviews

Entertainment

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Food

7.0

Overall

7.9

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well
Southwest
7.9
Good
4,301 reviews
Alaska Airlines
7.9
Good
12,353 reviews

Entertainment

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Food

7.0

Overall

7.9

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well
Delta
7.9
Good
8,451 reviews
Alaska Airlines
7.9
Good
12,353 reviews

Entertainment

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Food

7.0

Overall

7.9

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well
Hawaiian Airlines
7.8
Good
2,837 reviews
Alaska Airlines
7.9
Good
12,353 reviews

Entertainment

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Food

7.0

Overall

7.9

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well
American Airlines
7.1
Good
11,668 reviews
Alaska Airlines
7.9
Good
12,353 reviews

Entertainment

7.0

Crew

8.5

Boarding

8.1

Comfort

7.8

Food

7.0

Overall

7.9

Reviews

1 / 20
8.0
Excellent

Eugene,Mar 2026

MFR - SEA

Alaska Airlines is is always good. There where few choices of what to drink, and no food. No blankets, no pillows, and you h ats ok. I just had open heart surgery And i could have used something. But the flight and the crew where exelent. So all is well

Related info for your journey

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

  • What airport do you fly from for flights from St. Louis to Washington?

    For a flight from St. Louis to Washington, you will be flying from Lambert-St Louis. Lambert-St Louis (STL) is just 12.7 mi from the center of the city.

  • How popular is this St. Louis to State of Washington flight route?

    The Lambert-St Louis to Washington flight path was viewed by 36 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • How long is the flight from St. Louis to State of Washington?

    United Airlines, Delta, and Southwest can get you from St. Louis to State of Washington in just under 5h 45m. Your travel time can differ by up to 1h 40m. St. Louis and State of Washington are separated by a distance of 1702 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

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

    To fly one-way, consider booking your trip with Frontier, which is currently one of the cheapest options available, starting at $78. American Airlines flights start at $82 while deals on Delta start at $88 one-way.

  • What are the most popular routes from St. Louis to State of Washington?

    When deciding which route to take from St. Louis to State of Washington consider Lambert-St Louis - Seattle/Tacoma Intl, Lambert-St Louis - Portland or Lambert-St Louis - Spokane as they are the most popular.

  • What are the most reliable airlines from St. Louis to State of Washington?

    The top 3 most reliable airlines when flying from St. Louis to State of Washington are Japan Airlines (91%), Qatar Airways (91%) and Hawaiian Airlines (89%).

  • What are the cheapest flights from St. Louis to State of Washington?

    Looking for the cheapest flight from St. Louis to State of Washington? While on average our users pay $1,163, our data indicates the cheapest price to be $183. The most popular route (Lambert-St Louis - Seattle/Tacoma Intl), is priced around $238.

  • Can I find deals for flights from St. Louis to Washington that include hotel bookings?

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

  • How can I find direct flights from St. Louis to Washington?

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

  • Can I find deals for business class flights from St. Louis to Washington?

    Yes. Cheapflights offers flight deals from St. Louis to Washington 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 St. Louis to State of Washington?

    Currently, March is the cheapest month in which you can book a flight from St. Louis to State of Washington (average of $80). Flying from St. Louis to State of Washington in August is currently the most expensive (average of $169). 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 St. Louis to Washington

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

Discover the top 7 airlines that operate flights from St. Louis to Washington. 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 May 10, 2026.
AirlineCheapestAverageFlexibilityOn-time
DeltaCheapest$94Average$361FlexibilityNo cancel feeOn-timeN/A
FrontierCheapest$120Average$261FlexibilityNo cancel feeOn-time62%
Alaska AirlinesCheapest$151Average$404FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$176Average$420FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$178Average$417FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$188Average$408FlexibilityNo cancel feeOn-time71%
Hawaiian AirlinesCheapest$198Average$344FlexibilityNo cancel feeOn-time85%

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