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$90+ Cheap flights from Reagan-National (DCA) 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 9/20. Fares are subject to change and may not be available on all flights or dates of travel.
DCA — STL
août 23 — août 301
sam. 8/23
sam. 8/30
1 adult, Economy
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Cheapflights Tip: The best prices from Washington, D.C. Reagan-National to Lambert-St Louis are usually found in February or October, booked 76 days in advance, depart on a Wednesday or Monday and return on a Saturday

Cheap flight deals from Reagan-National to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Reagan-National (DCA) 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 août 18, 2025.

Round-trip from

$196
(FlightHub)

One-way from

$90
(CheapOair)

Popular in

August

Cheapest in

February

Average price

$389

Good round-trip deal

$219 or less

Good one-way deal

$158 or less
From Washington, D.C. Reagan-National to Lambert-St Louis
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One-way flight from Washington, D.C. Reagan-National to Lambert-St Louis
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Highest demand for flights based on searches. 4% potential increase in price ($14 potential increase over avg. RT price).
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Cheapest flight prices on average. 1% potential price decrease ($7 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. Reagan-National to Lambert-St Louis.
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Price to beat on a one-way flight from Washington, D.C. Reagan-National to Lambert-St Louis.
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Find flight deals from Reagan-National to St. Louis

Cheapest flights from Reagan-National to St. Louis
Explore the most affordable flight options available from Reagan-National to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on août 18, 2025.

This FlightHub 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sam. 9/67:00 amDCA - STL
1 stop27h 06mFrontier
lun. 9/87:55 pmSTL - DCA
1 stop20h 04mFrontier
Deal found 8/16$196
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.
jeu. 9/256:00 pmDCA - STL
1 stop16h 06mFrontier
dim. 9/287:55 pmSTL - DCA
1 stop15h 15mFrontier
Deal found 8/17$199
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.
sam. 9/201:00 pmDCA - STL
1 stop21h 06mFrontier
dim. 9/217:55 pmSTL - DCA
1 stop15h 15mFrontier
Deal found 8/17$201
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.
sam. 10/47:00 amDCA - STL
1 stop27h 06mFrontier
mar. 10/77:52 pmSTL - DCA
1 stop25h 07mFrontier
Deal found 8/16$205
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.
jeu. 9/256:00 pmDCA - STL
1 stop16h 06mFrontier
sam. 9/277:55 pmSTL - DCA
1 stop15h 15mFrontier
Deal found 8/16$215
This FlightHub 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mer. 9/171:00 pmDCA - STL
1 stop21h 06mFrontier
sam. 9/207:55 pmSTL - DCA
1 stop15h 15mFrontier
Deal found 8/16$221
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.
dim. 8/247:00 amDCA - STL
1 stop27h 11mFrontier
lun. 8/257:54 pmSTL - DCA
1 stop25h 05mFrontier
Deal found 8/17$227
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.
ven. 9/196:00 pmDCA - STL
1 stop16h 06mFrontier
dim. 9/217:55 pmSTL - DCA
1 stop15h 15mFrontier
Deal found 8/17$230
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.
sam. 8/236:00 pmDCA - STL
1 stop16h 11mFrontier
lun. 8/257:54 pmSTL - DCA
1 stop25h 05mFrontier
Deal found 8/17$231
This FlightHub 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 FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
ven. 10/171:00 pmDCA - STL
1 stop21h 07mFrontier
dim. 10/197:52 pmSTL - DCA
1 stop15h 12mFrontier
Deal found 8/16$234
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.
sam. 8/237:00 amDCA - STL
1 stop27h 11mFrontier
dim. 8/247:54 pmSTL - DCA
1 stop15h 17mFrontier
Deal found 8/17$236

Cheapflights Fare Finder

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

Fly from

Reagan-National

Fly to

St. Louis

Route

Depart

Return

Price

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

sam. 9/6

6:00 pm-9:06 am

1 stop16h 06m

Lambert-St Louis

lun. 9/8

7:55 pm-4:59 pm

1 stop20h 04m

$196

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

ven. 9/5

1:00 pm-9:06 am

1 stop21h 06m

Lambert-St Louis

ven. 9/12

7:55 pm-12:10 pm

1 stop15h 15m

$196

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

mar. 9/30

7:00 am-9:06 am

1 stop27h 06m

Lambert-St Louis

mer. 11/12

7:45 pm-12:04 pm

1 stop15h 19m

$196

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

ven. 10/3

1:00 pm-9:06 am

1 stop21h 06m

Lambert-St Louis

dim. 10/5

7:55 pm-12:10 pm

1 stop15h 15m

$196

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

dim. 9/14

6:00 pm-9:06 am

1 stop16h 06m

Lambert-St Louis

mer. 9/17

7:55 pm-12:10 pm

1 stop15h 15m

$196

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

sam. 10/18

6:00 pm-9:07 am

1 stop16h 07m

Lambert-St Louis

mar. 10/21

7:52 pm-12:04 pm

1 stop15h 12m

$196

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

mar. 9/2

7:00 am-9:11 am

1 stop27h 11m

Lambert-St Louis

mer. 9/3

7:54 pm-12:10 pm

1 stop15h 16m

$196

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

lun. 9/22

7:00 am-9:06 am

1 stop27h 06m

Lambert-St Louis

lun. 9/29

7:55 pm-9:59 pm

1 stop25h 04m

$196

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

ven. 10/3

7:00 am-9:06 am

1 stop27h 06m

$90

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

sam. 11/1

7:00 am-10:07 am

1 stop28h 07m

$90

Flights are sorted by cheapest round-trip flights first.

Deals found on 8/17

Showing 1-10 of 19 results
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The best insider tips for Washington, D.C. Reagan-National Airport 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. Reagan-National Airport to St. Louis trip
Airports
DCA

For a stress-free departure, reserve parking online at DCA as lots fill up quickly, especially during busy times.

Read more about DCAby Emily Zemler
STL

Use the MetroLink light rail for an economical and convenient ride from STL to downtown St. Louis, taking 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

Best time to book a flight from Reagan-National to St. Louis

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Reagan-National 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. Reagan-National Airport to St. Louis

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

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

The best time to book flights from Washington, D.C. Reagan-National Airport to St. Louis is 76 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

What is the cheapest month to book a flight from Washington, D.C. Reagan-National Airport to St. Louis?

Currently, August is the cheapest month in which you can book a flight from Washington, D.C. Reagan-National Airport to St. Louis (average of $311). Flying from Washington, D.C. Reagan-National Airport 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 DCA to STL?

Find hourly flight availability from Reagan-National 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 août 18, 2025.

It’s optimal to fly from Washington, D.C. Reagan-National Airport to St. Louis in the evening. By choosing this option you can save up to 17% on the cost of your flight, compared to a flight in the afternoon.

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

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

Travelers seeking maximum savings on their Washington, D.C. Reagan-National Airport 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. Reagan-National Airport to St. Louis

Explore weekly flight availability from Reagan-National 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 août 18, 2025.

The most flights from DCA to STL are scheduled on a Monday (8 on average). You will have fewer flight options on Saturday, which is when the least amount of flights are scheduled (4 on average).

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 août 18, 2025.
Peruse reviews from past customers who have flown with Southwest, Delta, and American Airlines from Washington, D.C. Reagan-National Airport to St. Louis to help guide your decision. 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
4,246 reviews

Food

7.0

Overall

8.0

Crew

8.6

Comfort

8.0

Entertainment

7.5

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

Food

7.0

Overall

8.0

Crew

8.6

Comfort

8.0

Entertainment

7.5

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

Food

7.0

Overall

8.0

Crew

8.6

Comfort

8.0

Entertainment

7.5

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

Food

7.0

Overall

8.0

Crew

8.6

Comfort

8.0

Entertainment

7.5

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 Reagan-National 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. Reagan-National?

    Lambert-St Louis (STL) is the airport you will fly into if you book a flight from Washington, D.C. Reagan-National to St. Louis. You should not have trouble finding flights to Lambert-St Louis from Washington, D.C. Reagan-National; the airport handles an average of 6 inbound flights from Washington, D.C. Reagan-National per day. You should also have plenty of airline options to choose from since 3 airlines have flights to the St. Louis airport from Washington, D.C. Reagan-National. It is only a 12.7 mi journey from Lambert-St Louis (STL) to St. Louis’s city center.

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

    For as low as $196, Frontier can have you in St. Louis from Washington, D.C. Reagan-National Airport in 16h 06m. The distance between Washington, D.C. Reagan-National Airport and St. Louis is about 717 mi.

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

    According to our current data, American Airlines ($176), Southwest ($189), and Delta ($223) offers the cheapest pricing from Washington, D.C. Reagan-National Airport to St. Louis. American Airlines is 45% cheaper than the average price of flights available within the next 90 days to this destination.

  • What are the most reliable airlines from Washington, D.C. Reagan-National Airport 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. Reagan-National Airport to St. Louis on time: Southwest (64%), PSA Airlines (62%), American Airlines (62%).

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

    Looking at all options, your cheapest flight can be booked for $89. While the most popular route (Washington, D.C. Reagan-National - Lambert-St Louis) can be booked for $167 on average our data indicates $423 when flying from Washington, D.C. Reagan-National Airport to St. Louis.

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

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

  • How can I find direct flights from Reagan-National to St. Louis?

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

  • Can I find deals for business class flights from Reagan-National to St. Louis?

    Yes. Cheapflights offers flight deals from Reagan-National 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. Reagan-National Airport to St. Louis?

    Currently, August is the cheapest month in which you can book a flight from Washington, D.C. Reagan-National Airport to St. Louis (average of $311). Flying from Washington, D.C. Reagan-National Airport 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

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Alternative routes for Reagan-National to St. Louis

See prices for flight routes from nearby airports that may be better suited for you.
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Top 3 airlines flying from Reagan-National to St. Louis

Discover the top 3 airlines that operate flights from Reagan-National 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 août 18, 2025.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$176Average$332FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$189Average$314FlexibilityNo cancel feeOn-time63%
DeltaCheapest$223Average$328FlexibilityNo cancel feeOn-timeN/A

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