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$128+ 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 8/29. Fares are subject to change and may not be available on all flights or dates of travel.
DCA — STL
Jul 6 — Jul 131
Mon 7/6
Mon 7/13
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 68 days in advance, depart on a Saturday or Thursday and return on a Tuesday

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 June 6, 2026.

This CheapOair deal was found by Cheapflights users on 6/1. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/146:00 pm
DCA
-
STL
1 stop26h 23m
Frontier
Mon 8/178:08 pm
STL
-
DCA
1 stop24h 51m
Frontier
Deal found 6/1$261
This CheapOair deal was found by Cheapflights users on 6/1. 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 CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 9/177:00 am
DCA
-
STL
1 stop13h 15m
Frontier
Sun 9/208:10 pm
STL
-
DCA
1 stop15h 39m
Frontier
Deal found 6/1$263
This Southwest deal was found by Cheapflights users on 6/1. 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 Southwest is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 7/206:40 pm
DCA
-
STL
Nonstop2h 20m
Southwest
Tue 7/211:10 pm
STL
-
DCA
Nonstop2h 00m
Southwest
Deal found 6/1$266
This Southwest deal was found by Cheapflights users on 6/2. 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.
Tue 7/73:00 pm
DCA
-
STL
Nonstop2h 15m
Southwest
Wed 7/83:35 pm
STL
-
DCA
1 stop6h 15m
Southwest
Deal found 6/2$267
This Mytrip deal was found by Cheapflights users on 6/1. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 8/77:00 am
DCA
-
STL
1 stop13h 23m
Frontier
Sun 8/98:08 pm
STL
-
DCA
1 stop15h 43m
Frontier
Deal found 6/1$269
This Southwest deal was found by Cheapflights users on 6/4. 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.
Fri 7/36:40 pm
DCA
-
STL
Nonstop2h 20m
Southwest
Mon 7/67:55 pm
STL
-
DCA
Nonstop2h 00m
Southwest
Deal found 6/4$272
This Expedia deal was found by Cheapflights users on 6/1. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 7/77:00 am
DCA
-
STL
1 stop13h 23m
Frontier
Tue 7/148:08 pm
STL
-
DCA
1 stop24h 51m
Frontier
Deal found 6/1$274
This American Airlines deal was found by Cheapflights users on 6/3. 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.
Sat 9/58:09 pm
DCA
-
STL
1 stop4h 49m
American Airlines
Mon 9/76:00 am
STL
-
DCA
Nonstop2h 14m
American Airlines
Deal found 6/3$275
This Expedia deal was found by Cheapflights users on 6/5. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/307:00 am
DCA
-
STL
1 stop13h 23m
Frontier
Thu 7/27:38 pm
STL
-
DCA
1 stop25h 21m
Frontier
Deal found 6/5$276
This Delta deal was found by Cheapflights users on 6/2. 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 Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 6/306:25 pm
DCA
-
STL
1 stop4h 53m
Delta
Tue 8/43:39 pm
STL
-
DCA
1 stop5h 06m
Delta
Deal found 6/2$277
This Southwest deal was found by Cheapflights users on 6/4. 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.
Thu 10/153:30 pm
DCA
-
STL
1 stop4h 30m
Southwest
Mon 10/193:50 pm
STL
-
DCA
Nonstop2h 00m
Southwest
Deal found 6/4$279

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 June 6, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$261
(CheapOair)

One-way from

$128
(Frontier)

Popular in

December

Cheapest in

August

Average price

$376

Good round-trip deal

$315 or less

Good one-way deal

$159 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. 7% potential increase in price ($30 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 June 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 June 6, 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

Cheapest round-trip

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Fri 7/3

6:40 pm-8:00 pm

Nonstop2h 20m

Lambert-St Louis

Mon 7/6

7:55 pm-10:55 pm

Nonstop2h 00m

$272

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Sat 7/4

8:15 am-9:25 am

Nonstop2h 10m

Lambert-St Louis

Sat 7/11

6:15 pm-9:20 pm

Nonstop2h 05m

$272

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Mon 7/20

6:40 pm-8:00 pm

Nonstop2h 20m

Lambert-St Louis

Tue 7/21

4:00 pm-11:50 pm

1 stop6h 50m

$276

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Sat 10/17

6:55 pm-8:15 pm

Nonstop2h 20m

Lambert-St Louis

Wed 10/28

5:40 am-1:25 pm

2 stops6h 45m

$280

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Wed 10/21

11:35 am-5:45 pm

2 stops7h 10m

Lambert-St Louis

Wed 10/28

8:30 am-3:55 pm

1 stop6h 25m

$282

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Wed 10/28

8:00 am-12:56 pm

1 stop5h 56m

Lambert-St Louis

Sat 10/31

11:51 am-6:14 pm

1 stop5h 23m

$285
Quickest round-trip

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Thu 7/2

8:00 am-9:10 am

Nonstop2h 10m

Lambert-St Louis

Mon 7/6

7:55 pm-10:55 pm

Nonstop2h 00m

$295

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Sat 7/4

10:10 am-6:00 pm

1 stop8h 50m

Lambert-St Louis

Mon 7/6

7:55 pm-10:55 pm

Nonstop2h 00m

$325

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Fri 7/17

2:35 pm-3:50 pm

Nonstop2h 15m

Lambert-St Louis

Sat 7/18

10:20 am-8:50 pm

2 stops9h 30m

$327

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Thu 7/23

8:25 am-12:11 pm

1 stop4h 46m

Lambert-St Louis

Fri 7/24

7:20 am-1:04 pm

1 stop4h 44m

$332

Flights are sorted by cheapest round-trip flights first.

Deals found on 6/4

Showing 1-10 of 21 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 June.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust 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?

The best time to book flights from Washington, D.C. Reagan-National Airport to St. Louis is 55 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 $275). Flying from Washington, D.C. Reagan-National Airport to St. Louis in December is currently the most expensive (average of $449). 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 June 6, 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 13% 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 May 30, 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. Sunday 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 Washington, D.C. Reagan-National Airport to St. Louis?

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 June 6, 2026.
Peruse reviews from past customers who have flown with Southwest 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
4,258 reviews

Overall

8.0

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.
Southwest
8.0
Very good
4,258 reviews
Southwest
8.0
Very good
4,258 reviews

Overall

8.0

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.
American Airlines
7.1
Good
11,649 reviews
Southwest
8.0
Very good
4,258 reviews

Overall

8.0

Comfort

8.0

Entertainment

7.5

Boarding

8.1

Crew

8.6

Food

7.0

Reviews

1 / 20
8.0
Excellent

La Tracimeldamarcos,Jun 2026

LAX - SLC

The second flight was not as comfortable as the first as we had to change planes to what seemed to be a slightly older aircraft. The seats weren’t as comfortable as the other plane. But it wasn’t bad.

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 2 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 $266, Frontier can have you in St. Louis from Washington, D.C. Reagan-National Airport in 2h 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 ($179), and Southwest ($204) offers the cheapest pricing from Washington, D.C. Reagan-National Airport to St. Louis. American Airlines is 50% 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 (73%), American Airlines (66%), PSA Airlines (66%).

  • 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 $128. While the most popular route (Washington, D.C. Reagan-National - Lambert-St Louis) can be booked for $257 on average, our data indicates $386 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 $275). Flying from Washington, D.C. Reagan-National Airport to St. Louis in December is currently the most expensive (average of $449). 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
Edwardsville
Fenton
Swansea
Fairview Heights
Maryland Heights
Collinsville
Eureka
Wentzville
Glencoe
Chesterfield
Alton
Farmington
Festus

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Top 2 airlines flying from Reagan-National to St. Louis

Discover the top 2 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 June 6, 2026.
AirlineCheapestAverageFlexibilityOn-time
American AirlinesCheapest$179Average$358FlexibilityNo cancel feeOn-time71%
SouthwestCheapest$204Average$376FlexibilityNo cancel feeOn-time63%

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