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$86+ 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 4/25. Fares are subject to change and may not be available on all flights or dates of travel.
DCA — STL
mar 31 — abr 71
ter 3/31
ter 4/7
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 August or October, booked 76 days in advance, depart on a Saturday or Tuesday and return on a Saturday

Cheap 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 março 1, 2026.

This American Airlines deal was found by Cheapflights users on 2/27. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
qua 3/257:30 am
DCA
-
STL
Nonstop2h 36m
American Airlines
qui 3/266:00 am
STL
-
DCA
Nonstop2h 12m
American Airlines
Deal found 2/27$267
This Southwest deal was found by Cheapflights users on 2/27. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
qui 5/288:00 am
DCA
-
STL
Nonstop2h 20m
Southwest
sáb 5/303:25 pm
STL
-
DCA
Nonstop2h 00m
Southwest
Deal found 2/27$269
This Southwest deal was found by Cheapflights users on 2/28. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
qui 4/235:00 pm
DCA
-
STL
1 stop6h 40m
Southwest
sáb 4/256:10 am
STL
-
DCA
2 stops9h 05m
Southwest
Deal found 2/28$270
This Southwest deal was found by Cheapflights users on 2/27. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
qui 4/163:35 pm
DCA
-
STL
1 stop4h 05m
Southwest
ter 4/217:55 pm
STL
-
DCA
Nonstop2h 05m
Southwest
Deal found 2/27$271
This Kiwi.com deal was found by Cheapflights users on 3/1. 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.
qua 4/158:00 am
DCA
-
STL
2 stops38h 00m
Frontier
seg 4/278:17 pm
STL
-
DCA
1 stop15h 43m
Frontier
Deal found 3/1$274
This American Airlines deal was found by Cheapflights users on 2/28. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
qua 4/11:45 pm
DCA
-
STL
Nonstop2h 34m
American Airlines
seg 4/66:00 am
STL
-
DCA
Nonstop2h 12m
American Airlines
Deal found 2/28$275
This American Airlines deal was found by Cheapflights users on 2/28. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sex 4/241:46 pm
DCA
-
STL
Nonstop2h 27m
American Airlines
sáb 5/26:00 am
STL
-
DCA
Nonstop2h 15m
American Airlines
Deal found 2/28$276
This Southwest deal was found by Cheapflights users on 2/26. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sex 4/248:00 am
DCA
-
STL
Nonstop2h 20m
Southwest
seg 4/277:40 pm
STL
-
DCA
Nonstop2h 00m
Southwest
Deal found 2/26$279
This American Airlines deal was found by Cheapflights users on 2/27. 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 American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
seg 3/237:30 am
DCA
-
STL
Nonstop2h 36m
American Airlines
ter 3/246:00 am
STL
-
DCA
Nonstop2h 12m
American Airlines
Deal found 2/27$280
This CheapOair deal was found by Cheapflights users on 2/25. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sex 3/138:00 am
DCA
-
STL
1 stop26h 49m
Frontier
seg 3/168:12 pm
STL
-
DCA
1 stop15h 50m
Frontier
Deal found 2/25$281

Find 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 março 1, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$267
(American Airlines)

One-way from

$86
(Booking.com)

Popular in

December

Cheapest in

August

Average price

$384

Good round-trip deal

$322 or less

Good one-way deal

$179 or less
Provider with most accurate pricing for Washington, D.C. Reagan-National-Lambert-St Louis flight deals.
Search Deals
Provider most trusted by Cheapflights users for Washington, D.C. Reagan-National-Lambert-St Louis flights.
Search Deals
From Washington, D.C. Reagan-National to Lambert-St Louis
Search Deals
One-way flight from Washington, D.C. Reagan-National to Lambert-St Louis
Search Deals
Highest demand for flights based on searches. 11% potential increase in price ($45 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 2% potential price decrease ($10 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 2026
Search Deals
Price to beat on a round-trip flight from Washington, D.C. Reagan-National to Lambert-St Louis.
Search Deals
Price to beat on a one-way flight from Washington, D.C. Reagan-National to Lambert-St Louis.
Search Deals

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 março 1, 2026.
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

Fly to

Route

Depart

Return

Price

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

qui 4/23

7:25 am-1:45 pm

2 stops7h 20m

Lambert-St Louis

sáb 4/25

6:10 am-4:15 pm

2 stops9h 05m

$275

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

qui 4/9

7:25 am-1:45 pm

2 stops7h 20m

Lambert-St Louis

sáb 4/11

6:10 am-4:15 pm

2 stops9h 05m

$298

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

sáb 6/20

4:10 pm-5:30 pm

Nonstop2h 20m

Lambert-St Louis

qui 6/25

1:20 pm-4:20 pm

Nonstop2h 00m

$317

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

ter 5/19

9:00 am-12:20 pm

1 stop4h 20m

Lambert-St Louis

dom 5/24

4:20 pm-11:24 pm

1 stop6h 04m

$318

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

sex 6/19

6:40 pm-8:00 pm

Nonstop2h 20m

Lambert-St Louis

dom 6/21

3:45 pm-10:50 pm

1 stop6h 05m

$349

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

sex 6/5

6:20 am-12:23 pm

1 stop7h 03m

Lambert-St Louis

dom 6/14

3:42 pm-10:20 pm

1 stop5h 38m

$359

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

sex 5/22

6:55 am-1:45 pm

1 stop7h 50m

Lambert-St Louis

dom 5/24

9:00 am-6:10 pm

1 stop8h 10m

$359

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

sex 5/1

7:25 am-1:45 pm

2 stops7h 20m

Lambert-St Louis

dom 5/3

4:40 pm-11:00 pm

1 stop5h 20m

$364

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

qui 4/16

3:30 pm-9:13 pm

1 stop6h 43m

Lambert-St Louis

seg 4/20

7:45 am-2:14 pm

1 stop5h 29m

$385

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

sex 3/20

1:55 pm-8:43 pm

1 stop7h 48m

Lambert-St Louis

seg 3/23

5:59 pm-10:51 pm

1 stop3h 52m

$391

Flights are sorted by cheapest round-trip flights first.

Deals found on 2/25

Showing 1-10 of 22 resultsSorted by cheapest first
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Compare providers for flights from Reagan-National to St. Louis

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.
Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from Reagan-National to St. Louis in March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
PricelinePrice Accuracy1 starTrust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

  • Most accurate provider: When it comes to deals on Washington, D.C. Reagan-National Airport-St. Louis flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on Washington, D.C. Reagan-National Airport-St. Louis flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from Washington, D.C. Reagan-National Airport-St. Louis flight searches over the past month and is updated monthly.
  • Most trusted provider: When it comes to deals on Washington, D.C. Reagan-National Airport-St. Louis flights, Cheapflights users trust FlightHub the most. FlightHub has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for Washington, D.C. Reagan-National Airport-St. Louis flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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 February 27, 2026.

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, September is the cheapest month in which you can book a flight from Washington, D.C. Reagan-National Airport to St. Louis (average of $151). Flying from Washington, D.C. Reagan-National Airport to St. Louis in December is currently the most expensive (average of $282). 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 março 1, 2026.

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 February 21, 2026.

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

The best insider tips for Washington, D.C. Reagan-National Airport to St. Louis flights

AI-powered summary based on content written by travel experts. AI can make mistakes.
Cheapflights partnered with top experts to bring you the best recommendations for your Washington, D.C. Reagan-National Airport to St. Louis trip
Our travel experts
Emily Zemler

Emily Zemler

Expert on DCA

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 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

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 março 1, 2026.
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
4,303 reviews

Crew

8.6

Food

7.0

Comfort

8.0

Entertainment

7.5

Overall

8.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Feb 2026

DEN - BDL

Weird they cancelled a direct and rerouted me on a connecting flight to get in 10 hours later. What was the point? Crew and flight were great, but not sure what's going on with Southwest.
Southwest
8.0
Very good
4,303 reviews
Southwest
8.0
Very good
4,303 reviews

Crew

8.6

Food

7.0

Comfort

8.0

Entertainment

7.5

Overall

8.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Feb 2026

DEN - BDL

Weird they cancelled a direct and rerouted me on a connecting flight to get in 10 hours later. What was the point? Crew and flight were great, but not sure what's going on with Southwest.
Delta
7.9
Good
8,244 reviews
Southwest
8.0
Very good
4,303 reviews

Crew

8.6

Food

7.0

Comfort

8.0

Entertainment

7.5

Overall

8.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Feb 2026

DEN - BDL

Weird they cancelled a direct and rerouted me on a connecting flight to get in 10 hours later. What was the point? Crew and flight were great, but not sure what's going on with Southwest.
American Airlines
7.2
Good
11,370 reviews
Southwest
8.0
Very good
4,303 reviews

Crew

8.6

Food

7.0

Comfort

8.0

Entertainment

7.5

Overall

8.0

Boarding

8.1

Reviews

1 / 20
8.0
Excellent

Anonymous,Feb 2026

DEN - BDL

Weird they cancelled a direct and rerouted me on a connecting flight to get in 10 hours later. What was the point? Crew and flight were great, but not sure what's going on with Southwest.

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 4 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 $318, Southwest can have you in St. Louis from Washington, D.C. Reagan-National Airport in 4h 20m. The distance between Washington, D.C. Reagan-National Airport and St. Louis is about 717 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • 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 ($167), Southwest ($187), and Delta ($216) offers the cheapest pricing from Washington, D.C. Reagan-National Airport to St. Louis. American Airlines is 51% 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: Republic Airways (94%), Southwest (79%), American Airlines (78%).

  • 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 $145. While the most popular route (Washington, D.C. Reagan-National - Lambert-St Louis) can be booked for $191 on average, our data indicates $598 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, September is the cheapest month in which you can book a flight from Washington, D.C. Reagan-National Airport to St. Louis (average of $151). Flying from Washington, D.C. Reagan-National Airport to St. Louis in December is currently the most expensive (average of $282). 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
Edwardsville
O'Fallon
Swansea
Fairview Heights
Fenton
Maryland Heights
Collinsville
Eureka
Wentzville
Glencoe
Chesterfield
Alton
Farmington
Festus

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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 março 1, 2026.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$167Average$330FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$188Average$347FlexibilityNo cancel feeOn-time63%
DeltaCheapest$216Average$323FlexibilityNo cancel feeOn-timeN/A

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