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$72+ Cheap flights from Washington, D.C. (WAS) to St. Louis (STL)

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 10/24. Fares are subject to change and may not be available on all flights or dates of travel.
WAS — STL
Aug 23 — Aug 301
Sat 8/23
Sat 8/30
1 adult, Economy
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Cheapflights Tip: The best prices from Washington, D.C. to Lambert-St Louis are usually found in August or May, booked 90 days in advance, depart on a Wednesday or Friday and return on a Friday

Cheap flight deals from Washington, D.C. to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Washington, D.C. (WAS) to St. Louis (STL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated August 18, 2025.

Round-trip from

$143
(CheapOair)

One-way from

$72
(CheapOair)

Popular in

March

Cheapest in

August

Average price

$277

Good round-trip deal

$219 or less

Good one-way deal

$158 or less
From Washington, D.C. (WAS) to Lambert-St Louis
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One-way flight from Washington, D.C. (WAS) to Lambert-St Louis
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Highest demand for flights based on searches. 8% potential increase in price ($30 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($4 potential savings vs. average RT price).
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Average for round-trip flights in August 2025
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Price to beat on a round-trip flight from Washington, D.C. (WAS) to Lambert-St Louis.
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Price to beat on a one-way flight from Washington, D.C. (WAS) to Lambert-St Louis.
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Find flight deals from Washington, D.C. to St. Louis

Cheapest flights from Washington, D.C. to St. Louis
Explore the most affordable flight options available from Washington, D.C. to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on August 18, 2025.

This CheapOair deal was found by Cheapflights users on 8/18. 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.
Sun 9/710:13 amBWI - STL
1 stop27h 49mFrontier
Mon 9/224:00 pmSTL - BWI
1 stop7h 17mFrontier
Deal found 8/18$143
This Priceline deal was found by Cheapflights users on 8/17. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/186:22 amBWI - STL
1 stop9h 42mFrontier
Sun 9/214:00 pmSTL - BWI
1 stop7h 17mFrontier
Deal found 8/17$144
This CheapOair deal was found by Cheapflights users on 8/17. 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 9/116:22 amBWI - STL
1 stop9h 42mFrontier
Sun 9/1410:39 amSTL - BWI
1 stop6h 21mFrontier
Deal found 8/17$149
This CheapOair deal was found by Cheapflights users on 8/17. 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 9/46:22 amBWI - STL
1 stop9h 42mFrontier
Sat 9/67:55 pmSTL - BWI
1 stop20h 47mFrontier
Deal found 8/17$153
This Priceline deal was found by Cheapflights users on 8/16. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 8/236:50 amBWI - STL
1 stop7h 43mFrontier
Sat 8/233:02 pmSTL - BWI
1 stop8h 06mFrontier
Deal found 8/16$154
This FlightHub deal was found by Cheapflights users on 8/17. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 11/79:13 amBWI - STL
1 stop7h 21mFrontier
Sun 11/911:17 amSTL - BWI
1 stop11h 56mFrontier
Deal found 8/17$165
This FlightHub deal was found by Cheapflights users on 8/17. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 9/202:21 pmBWI - STL
1 stop20h 33mFrontier
Sun 9/214:00 pmSTL - BWI
1 stop26h 10mFrontier
Deal found 8/17$166
This CheapOair deal was found by Cheapflights users on 8/17. 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.
Sun 9/76:22 amBWI - STL
1 stop9h 42mFrontier
Sun 9/214:00 pmSTL - BWI
1 stop7h 17mFrontier
Deal found 8/17$169
This FlightHub deal was found by Cheapflights users on 8/18. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 10/176:29 pmBWI - STL
1 stop15h 38mFrontier
Sun 10/1911:32 amSTL - BWI
1 stop20h 33mFrontier
Deal found 8/18$170
This FlightHub deal was found by Cheapflights users on 8/18. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 10/156:45 pmBWI - STL
1 stop16h 52mFrontier
Sun 10/1911:32 amSTL - BWI
1 stop20h 33mFrontier
Deal found 8/18$171
This CheapOair deal was found by Cheapflights users on 8/16. 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.
Fri 10/36:27 pmBWI - STL
1 stop15h 39mFrontier
Sun 10/51:57 pmSTL - BWI
1 stop24h 20mFrontier
Deal found 8/16$174
This FlightHub deal was found by Cheapflights users on 8/17. 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 10/94:40 pmIAD - STL
1 stop18h 57mFrontier
Sun 10/1210:17 amSTL - IAD
1 stop21h 52mFrontier
Deal found 8/17$181

Cheapflights Fare Finder

 
Customize your flight search to find flights from Washington, D.C. to St. Louis 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 August 18, 2025.
Use the filters below to find and compare flights from Washington, D.C. to St. Louis that are best for you.

Fly from

Washington, D.C.

Fly to

St. Louis

Route

Depart

Return

Price

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Thu 9/4

6:22 am-3:04 pm

1 stop9h 42m

Lambert-St Louis

Fri 9/5

1:57 pm-3:29 pm

1 stop24h 32m

$143

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Mon 9/15

6:22 am-3:04 pm

1 stop9h 42m

Lambert-St Louis

Mon 9/22

4:00 pm-12:17 am

1 stop7h 17m

$143

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Sun 9/7

6:22 am-3:04 pm

1 stop9h 42m

Lambert-St Louis

Mon 9/22

4:00 pm-12:17 am

1 stop7h 17m

$143

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Thu 9/18

6:22 am-3:04 pm

1 stop9h 42m

Lambert-St Louis

Sun 9/21

4:00 pm-12:17 am

1 stop7h 17m

$143

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Thu 9/11

6:22 am-3:04 pm

1 stop9h 42m

Lambert-St Louis

Sun 9/14

10:39 am-6:00 pm

1 stop6h 21m

$149

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Fri 9/12

6:27 pm-9:06 am

1 stop15h 39m

Lambert-St Louis

Mon 9/15

4:00 pm-12:17 am

1 stop7h 17m

$153

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Fri 10/3

6:27 pm-9:06 am

1 stop15h 39m

Lambert-St Louis

Sun 10/5

4:00 pm-12:17 am

1 stop7h 17m

$153

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Thu 9/4

6:22 am-3:04 pm

1 stop9h 42m

Lambert-St Louis

Sat 9/6

7:55 pm-5:42 pm

1 stop20h 47m

$153

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Mon 8/25

6:10 am-12:56 pm

1 stop7h 46m

Lambert-St Louis

Mon 8/25

2:01 pm-12:19 am

1 stop9h 18m

$154

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Fri 10/17

6:29 pm-9:07 am

1 stop15h 38m

Lambert-St Louis

Mon 10/20

6:05 pm-10:20 am

1 stop15h 15m

$154

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/16

Showing 1-10 of 52 results
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The best insider tips for Washington, D.C. to St. Louis flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your Washington, D.C. to St. Louis trip
Airports
DCA

DCA is easily accessible via the Metro, offering a clean and affordable way to reach the airport from D.C. and nearby Maryland.

Read more about DCAby Emily Zemler
IAD

IAD's Aerotrain connects the main terminal to concourses, but pay attention to signage for the correct train direction.

Read more about IADby Ramsey Qubein
STL

STL's MetroLink offers a convenient and economical way to reach downtown St. Louis in about 40 minutes.

Read more about STLby Taryn White
Our travel experts
Emily Zemler

Emily Zemler

Expert on DCA

Emily Zemler

Emily Zemler

Emily is a freelance writer and book author based in London covering entertainment and travel. Her work has appeared in Los Angeles Times, Observer, and Conde Nast Traveler She has ventured to more than 40 countries and all seven continents, always in search of a great art museum. She has written extensively about hotels, luxury travel, and aviation.

Read more
Taryn White

Taryn White

Expert on STL

Taryn White

Taryn White

Taryn White is a freelance travel writer, digital creator, and travel advisor who has visited nearly 100 countries and all 50 states. She’s familiar with many airports and enjoys beach hopping, boutique hotels, spa experiences, and exploring local culture. Her work has appeared in Travel + Leisure, Condé Nast Traveler, National Geographic, Smithsonian Magazine, AFAR, and more.

Read more
Ramsey Qubein

Ramsey Qubein

Expert on IAD

Ramsey Qubein

Ramsey Qubein

An avid traveler and aviation expert who has visited 173 countries, all 50 states and seven continents, Ramsey Qubein flies nearly 400,000 miles a year. As a North Carolina-based freelance journalist for publications including Conde Nast Traveler, Forbes, USA Today and Bloomberg among others, he explores the latest trends in aviation, hospitality, cruises and business.

Read more

Best time to book a flight from Washington, D.C. to St. Louis

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

How far ahead should I book a flight from Washington, D.C. to St. Louis?

Use this chart to determine the optimal time to book a round-trip flight from Washington, D.C. to St. Louis. Price data was last updated on August 8, 2025.

To ensure you get the cheapest price possible for a flight from Washington, D.C. to St. Louis, you should look to book at least 90 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 Washington, D.C. to St. Louis?

Currently, August is the cheapest month in which you can book a flight from Washington, D.C. to St. Louis (average of $311). Flying from Washington, D.C. to St. Louis in March is currently the most expensive (average of $356). 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 WAS to STL?

Find hourly flight availability from Washington, D.C. to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated August 18, 2025.

It’s optimal to fly from Washington, D.C. to St. Louis in the evening. By choosing this option you can save up to 19% on the cost of your flight, compared to a flight in the afternoon.

What is the cheapest day to fly from Washington, D.C. to St. Louis?

Use this chart to determine the cheapest time to fly round-trip from Washington, D.C. to St. Louis. Price data was last updated on August 17, 2025.

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

Weekly flight availability from Washington, D.C. to St. Louis

Explore weekly flight availability from Washington, D.C. to St. Louis. 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 August 18, 2025.

The most flights from WAS to STL are scheduled on a Monday (16 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (5 on average).

How much does it cost to fly round-trip from Washington, D.C. to St. Louis?

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. 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 St. Louis. Reviews last updated August 18, 2025.
See what other customers who have flown with Southwest, Delta, and United Airlines from Washington, D.C. to St. Louis have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Southwest
8.0
Very good
4,246 reviews
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Delta
8.0
Very good
7,981 reviews
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
United Airlines
7.4
Good
8,925 reviews
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
American Airlines
7.2
Good
10,000 reviews
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.
Frontier
5.8
Fair
3,212 reviews
Southwest
8.0
Very good
4,246 reviews

Overall

8.0

Crew

8.6

Entertainment

7.5

Comfort

8.0

Food

7.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Walter,Aug 2025

OAK - SAN

Dozens of flights and I've never seen a row's beverages forgotten. I even went back and asked the attendant to check on them and nothing. I really hope it didn't have something to do with the Black mother with her kid in the row. Otherwise it was a typical Southwest flight, rapid boarding, tolerable leg room.

Related info for your journey

Find useful and relevant information for your journey from Washington, D.C. to St. Louis. 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 into for flights to St. Louis from Washington, D.C.?

    Lambert-St Louis (STL), located 12.7 mi from the city center, is the airport you fly into when you book flights from Washington, D.C. to St. Louis. 5 airlines have flights to Lambert-St Louis from Washington, D.C. on a regular basis. Booking flights from Washington, D.C. to Lambert-St Louis should not be difficult; the airport handles an average of 10 inbound flights from Washington, D.C. per day.

  • How long is the flight from Washington, D.C. to St. Louis?

    A quick flight from Washington, D.C. to St. Louis can take about 9h 42m. Frontier provides one of the quickest options available for as low as $143. There are 736 mi between Washington, D.C. and St. Louis.

  • What are the cheapest airlines flying from Washington, D.C. to St. Louis round-trip?

    Our cheapest airline available from Washington, D.C. to St. Louis is American Airlines. Our recent data shows that you can find tickets from as low as $174 on this airline. Additional options worth looking into are Southwest and Delta, starting at $188 and $196 round-trip. These flights start at 46% lower than the current average price 3 months from now.

  • What are the most popular routes from Washington, D.C. to St. Louis?

    When deciding which route to take from Washington, D.C. to St. Louis consider Baltimore/Washington - Lambert-St Louis, Washington, D.C. Dulles Intl - Lambert-St Louis or Washington, D.C. Reagan-National - Lambert-St Louis as they are the most popular.

  • What are the most reliable airlines from Washington, D.C. to St. Louis?

    Looking for the most reliable airlines to get you to your destination on time? Our data shows these are most likely to get you from Washington, D.C. to St. Louis on time: GoJet (74%), Avianca (73%), Copa Airlines (73%).

  • What are the cheapest flights from Washington, D.C. to St. Louis?

    The cheapest flight price from Washington, D.C. to St. Louis is $212. On average you can expect to pay $489. The most popular route, (Baltimore/Washington - Lambert-St Louis), can usually be booked for $165.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Washington, D.C. to St. Louis 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 Washington, D.C. to St. Louis?

    Currently, August is the cheapest month in which you can book a flight from Washington, D.C. to St. Louis (average of $311). Flying from Washington, D.C. to St. Louis in March is currently the most expensive (average of $356). 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

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
O'Fallon
Fairview Heights
Maryland Heights
Collinsville
Eureka
St. Peters
Glencoe
Alton
Chesterfield
Farmington
Festus

Browse thousands of different options on Cheapflights for your next trip

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Top 5 airlines flying from Washington, D.C. to St. Louis

Discover the top 5 airlines that operate flights from Washington, D.C. to St. Louis. 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 August 18, 2025.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$108Average$175FlexibilityNo cancel feeOn-time62%
American AirlinesCheapest$158Average$326FlexibilityNo cancel feeOn-time71%
DeltaCheapest$169Average$279FlexibilityNo cancel feeOn-timeN/A
SouthwestCheapest$189Average$345FlexibilityNo cancel feeOn-time63%
United AirlinesCheapest$255Average$481FlexibilityNo cancel feeOn-time69%

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