STL - WAS

$70 Find Cheap Flights from St. Louis to Washington, D.C.

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from St. Louis to Washington, D.C. departing on 5/12. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

KAYAK searches hundreds of travel sites at once for deals on flights to Washington, D.C.

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Washington, D.C., as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Washington, D.C., as well as popular online travel agencies
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Everything you should know

Cheapest round-trip
$145
Overall average: $307
Frontier
Tue 5/12Tue 5/19
STL - BWI • 1 stop
Cheapest non-stop
$246
Typical prices: $258-$441
American Airlines
Wed 4/15Sat 4/18
STL - DCA • Non-stop
Advice from real travelers
AI-powered summary based on content written by travel experts. AI can make mistakes.
Southwest's two free checked bags save on fees.
DCA is the closest airport to downtown D.C.
Expert advice
Expert advice
Expert advice
Expert advice
Top airlines
Cheapest • from $145 (round-trip)
Best reviews • 8.0 score
Airline reviews
Airline reviews
+1
+1
Airline reviews
Airline reviews
+1
Nonstop flights
You can fly direct with American Airlines, Southwest and United Airlines. Average duration is 2h 02m
Direct flights
Direct flights
+1
+1
Direct flights
Direct flights
+1
Top routes
Cheapest • 19% average savings
Most popular
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $169 (round-trip)
Shortest trip • 3h 55m (one-way)
Insights
Insights
Insights
Insights
When to book
in advance
Our data shows that travelers who book at least 3 weeks in advance save around 36% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 25% price drop
Most popular
Good to know
Good to know
+1
+1
Good to know
Good to know
+1
Start a new search
KAYAK searches 100s of sites at once to find you the best travel deals.
We hope you love your trip to Washington, D.C.!
Flight Deals
Booking Insights
Expert advice
Flight Deals

Cheap Flights from St. Louis to Washington, D.C. (STL-WAS)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Washington, D.C. that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals from St. Louis to Washington, D.C.

Tue, May 12 - Tue, May 19
Frontier Logo
6:33 pm - 7:43 am
STL
-
BWI
12h 10m
1 stop
Frontier Logo
9:25 pm - 8:55 am
BWI
-
STL
12h 30m
1 stop
$145Frontier
Wed, May 13 - Tue, May 19
Frontier Logo
5:27 pm - 7:43 am
STL
-
BWI
13h 16m
1 stop
Frontier Logo
9:25 pm - 8:55 am
BWI
-
STL
12h 30m
1 stop
$155Frontier
Mon, Apr 20 - Tue, Apr 21
Frontier Logo
8:23 pm - 11:22 am
STL
-
BWI
13h 59m
1 stop
Frontier Logo
5:49 pm - 6:50 am
BWI
-
STL
14h 01m
1 stop
$159Frontier
Wed, Apr 15 - Sat, Apr 18
American Airlines Logo
6:00 am - 9:15 am
STL
-
DCA
2h 15mnonstop
American Airlines Logo
7:59 pm - 9:25 pm
DCA
-
STL
2h 26mnonstop
$246American Airlines
Wed, Apr 1 - Tue, Apr 7
Southwest Logo
7:30 am - 3:00 pm
STL
-
DCA
6h 30m
1 stop
Southwest Logo
6:55 pm - 8:20 pm
DCA
-
STL
2h 25mnonstop
$247Southwest
Wed, Apr 15 - Sat, Apr 18
American Airlines Logo
6:00 am - 9:15 am
STL
-
DCA
2h 15mnonstop
American Airlines Logo
7:59 pm - 9:25 pm
DCA
-
STL
2h 26mnonstop
$251American Airlines
Tue, Apr 21 - Tue, Apr 21
United Airlines Logo
6:15 am - 12:30 pm
STL
-
DCA
5h 15m
1 stop
United Airlines Logo
6:03 pm - 9:52 pm
DCA
-
STL
4h 49m
1 stop
$252United Airlines
Thu, Apr 9 - Mon, Apr 13
Multiple Airlines Logo
6:29 pm - 4:49 pm
STL
-
IAD
21h 20m
1 stop
Multiple Airlines Logo
2:58 pm - 11:25 pm
IAD
-
STL
9h 27m
2 stops
$252Multiple Airlines
Wed, Apr 1 - Thu, Apr 9
Southwest Logo
8:25 am - 11:20 am
STL
-
DCA
1h 55mnonstop
Southwest Logo
6:45 pm - 8:10 pm
DCA
-
STL
2h 25mnonstop
$254Southwest
Wed, Apr 8 - Wed, Apr 15
United Airlines Logo
11:15 am - 5:04 pm
STL
-
DCA
4h 49m
1 stop
United Airlines Logo
7:30 am - 12:22 pm
DCA
-
STL
5h 52m
1 stop
$257United Airlines
Booking Insights

KAYAK's insights & trends for St. Louis to Washington, D.C. flights

Get data-powered insights and trends into flights from St. Louis to Washington, D.C. to help you find the cheapest flights, the best time to fly and much more.

How much is a round-trip flight from St. Louis to Washington, D.C.?

This analysis is based on the cheapest round-trip price found on KAYAK in the last 12 months by searching for a flight from St. Louis to Washington, D.C. departing in May.

What is the cheapest St. Louis to Washington, D.C. flight route?

Data is based on round-trip flight searches on KAYAK over the past month.

The cheapest return flight from St. Louis to Washington, D.C. costs $255 on the route between St. Louis (STL) and Washington, D.C. Reagan-National Airport (DCA). Over the past month, this route was, on average, 19% cheaper than other St. Louis-Washington, D.C. routes. It is also the most popular route.

What’s the cheapest day of the week to fly from St. Louis to Washington, D.C.?

The average price of all round-trip flights from St. Louis to Washington, D.C. clicked on KAYAK for each day over the last 12 months.

For St. Louis to Washington, D.C., Friday is the cheapest day to fly on average and Thursday is the most expensive. Flying from Washington, D.C. back to St. Louis, the best deals are generally found on Wednesday, with Monday being the most expensive.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from St. Louis to Washington, D.C., removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from St. Louis to Washington, D.C. is August, where tickets cost $229 (return) on average. On the other hand, the most expensive months are March and February, where the average cost of round-trip tickets is $365 and $361 respectively.

Can I save money by flying with a layover from St. Louis to Washington, D.C.?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.

No, with an average price for the route of $370, prices are generally cheapest when you fly direct.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from St. Louis to Washington, D.C., removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.

To get a below average price on the flight from St. Louis to Washington, D.C., you should book around 3 weeks before departure, which saves you about 36% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 15 weeks before departure.

Expert advice

Expert advice for your flight from St. Louis to Washington, D.C.

 
AI-powered summary based on content written by travel experts. AI can make mistakes.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Stefanie Waldek

Stefanie Waldek

Expert on United Airlines, DCA and IAD

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or on the sea, likely en route to Antarctica or the Arctic.

Blane Bachelor

Blane Bachelor

Expert on Southwest

Blane Bachelor is a journalist and editor specializing in travel and aviation who writes regularly for top global outlets. Born and raised in Florida, Blane has worked and lived in four countries, including the Netherlands, where she’s currently based with her family. Her favorite way to get to know a new destination is by running or riding a bike around town – or hearing a spooky ghost story about local history. She will always choose the window seat.

Harriet Baskas

Harriet Baskas

Expert on American Airlines

Harriet is an award-winning journalist who is happiest in an airport or an unusual museum. Her stories about airports, air travel, and the business of travel have appeared on NBC News, CNBC, USA TODAY, The Points Guy and other outlets. She is the creator of the StuckatTheAirport.com blog and the author of nine books. When not out on the road or exploring the latest airport amenities, she’s home in Seattle getting ready for the next adventure.

Yulia Denisyuk

Yulia Denisyuk

Expert on STL

Yulia is a freelance journalist who’s dispatched from 90+ countries. Her work focuses on cultures, adventure trips and air travel, appearing in NatGeo, NYT, CNTraveler, and more. For past assignments, she’s stayed with nomads in Mongolia and learned the art of Imigongo in Rwanda. She’s based in Chicago; in winter she often questions that decision.

Good to know

Low seasonFebruary
Cheapest flight$70
Best time to beat the crowds but there is an average 18% increase in price.
Most popular time to fly and prices are also 4% lower on average.
Flight from St. Louis to Baltimore

When to book flights from St. Louis to Washington, D.C.

Are your dates flexible? Find out the best times to travel from St. Louis to Washington, D.C. based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking flights from St. Louis to Washington, D.C.

  • What is the cheapest flight from St. Louis to Washington, D.C.?

    In the last 3 days, the lowest price for a flight from St. Louis to Washington, D.C. was $70 for a one-way ticket and $145 for a round-trip.

  • Do I need a passport to fly between St. Louis and Washington, D.C.?

    No

  • Which airports will I be using when flying from St. Louis to Washington, D.C.?

    On your way to Washington, D.C., you’ll fly out from Lambert-St Louis. You’ll be landing in one of Washington, D.C.’s 2 airports: Washington, D.C. Reagan-National or Washington, D.C. Dulles Intl.

  • Which airlines offer Wi-Fi service onboard planes from St. Louis to Washington, D.C.?

    All the following airlines offer inflight Wi-Fi service on the St. Louis to Washington, D.C. flight route: American Airlines, JetBlue, Alaska Airlines, Lufthansa, Delta, and Air Canada.

  • Which aircraft models fly most regularly from St. Louis to Washington, D.C.?

    The Boeing 737 MAX 8 is the aircraft model that flies most regularly on the St. Louis to Washington, D.C. flight route.

  • Which airline alliances offer flights from St. Louis to Washington, D.C.?

    SkyTeam, Star Alliance, and oneworld are the airline alliances operating flights between St. Louis and Washington, D.C., with SkyTeam being the most commonly used for this route.

  • On which days can I fly direct from St. Louis to Washington, D.C.?

    There are nonstop flights from St. Louis to Washington, D.C. on a daily basis.

  • Which is the best airline for flights from St. Louis to Washington, D.C., Southwest or Delta?

    The two airlines most popular with KAYAK users for flights from St. Louis to Washington, D.C. are Southwest and Delta. With an average price for the route of $325 and an overall rating of 8.0, Southwest is the most popular choice. Delta is also a great choice for the route, with an average price of $292 and an overall rating of 7.9.

  • How does KAYAK find such low prices on flights from St. Louis to Washington, D.C.?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from St. Louis to Washington, D.C..

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from St. Louis to Washington, D.C.?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Washington, D.C. from St. Louis is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from St. Louis to Washington, D.C.?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Washington, D.C. with an airline and back to St. Louis with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from St. Louis to Washington, D.C.?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Washington, D.C. from St. Louis up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

KAYAK’s top tips for finding a cheap flight from St. Louis to Washington, D.C.

  • Looking for a cheap flight? 25% of our users found flights on this route for $340 or less one-way and $443 or less round-trip.

Prefer to fly direct from St. Louis to Washington, D.C.?

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Lambert-St Louis to Washington, D.C..
Find which airlines fly direct from Lambert-St Louis Airport to Washington, D.C., which days they fly and book direct flights.

Direct departures

Lambert-St Louis to Washington, D.C.

Monday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Tuesday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Wednesday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Thursday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Friday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Saturday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Sunday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

See more direct flights

Direct returns

Washington, D.C. to Lambert-St Louis

Monday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Tuesday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Wednesday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Thursday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Friday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Saturday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

Sunday

American Airlines,Southwest,United Airlines

American Airlines,Southwest, +1 more

See more direct flights

Reviews of the top 4 airlines serving from St. Louis to Washington, D.C.

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to Washington, D.C.. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from St. Louis to Washington, D.C.? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
SouthwestOverall score based on 4318 reviews
7.5Entertainment
8.1Boarding
7.0Food
8.6Crew
8.0Comfort
Airline reviews

Long layover between flights to Long Island from BWI - need better coordination between flights

4.0 OkayKenny, Mar 2026
TPA - BWI
Read more Southwest reviews

Long layover between flights to Long Island from BWI - need better coordination between flights

I elected to pay for the upgrades and found very little difference

The new seating arrangement is so over priced for what you get.

The problem with the seat assignments is that there were a lot of rows in the front that were empty but my row at the back was full. Just not so pleasant.

No food or entertainment, just a quick 40 minute flight. A little bumpy due to Santa Ana winds but pilot has no control over that. Good flight and landing!

Good but I prefer choose your own seat. With the new assigned seats they should board from the back I see no advantage to this new boarding. Just like every other airline

I realize they are still working out kinks with the new boarding process, but by the time I boarded in group 5, most of the bins were full. All airlines should better enforce small bags and jackets going under the seats until everyone has boarded.

WiFi was not working and didn’t have a beverage service

Snacks are always pretzels. Why can't you also offer peanuts ?

Flight boarded late after announcing on time boarding. Flight arrived only a little late despite late departure. Had trouble connecting to WiFi

We landed and sat on the tarmac for 45 minutes because they only have one gate at the airport and there was another plane running late so we had to wait

The WiFi was not working. That made for a long flight.

Absolutely no communication on why there's a delay and multiple flight time reschedules. I would have canceled the flight and drove back home if I known it was going to be rescheduled 3 or 4 times.

Another late night flight and MORE men belligerently drinking and yelling. I had to move from first to economy because they were so obnoxious and disruptive. Crazy to go from a cozy chair to cardboard when you were supposed to be in first. Delta allows was too much drinking which leads to belligerent behavior.

I was in first class and literally the men behind me were so aggressively loud I moved myself to economy. This has become so common on Delta - people using audio without headphones, and men on 12am / late night flights drinking and yelling to talk to each other which prevents anyone around them from resting. Pretty crazy to have to move from first to economy (poorer service, less comfort...). Wild wild. Looking into other airlines.

Love delta smaller commuter plane so no entertainment and paid wifi on MKE-LGA leg was extremely unreliable and slow

Stop changing gates. Stop cancelling flights Stop moving my seat.

Extremely disappointed with Delta. They canceled flight last minute and then I rebooked the other flights and with which were delayed as well

Could not get my connecting flight boarding pass until four hrs before departure! Ver annoying especially since the staff could not explain why!

The flight was flying with 30% capacity. The flight my seat from preferred seating to back of the seat. Even though i can understand that this was to balance the flight weight. The flight attendance decided to do the serving near my seat and in the middle , their noices woke me up from sleep , when i realized that the service has ended and when they were going back asked for a coffee, for which they answered they have completed teh service in my location. That really upset me as they woke me up and also rejected the coffee i asked. I ended up landing with a headache, thanks to the crew that screwed up my travel

Easy boarding. Rows are smaller but that may be an older and bigger me now :)

Flight has been delayed every time I've ever taken it. Seats uncomfortable. Children behind me yelling the entire flight. Some of this is out of their control but overall just consistently not a great experience.

Poor communication ahead of time about flight delays and old planes/other equipment.

Never going to fly your airline again if it can be avoided.

Not to have gotten delayed by 2+ hours for the fourth straight American flight. They're the worst.

Other than nearly three hour delay for maintenance issues, everything went smooth

Snow delayed boarding several times, which I understand happens. Issue I had was that after we did board, pilot told us we were going to roll out to be de-iced, then on our way. We were de-iced once, taxied to the tarmac and then stopped. Sat for another 30 minutes or so, the another de-icing. Then we rolled out to a parking spot, only to sit for another hour due to a traffic stop in DCA, which I'm confident they knew would happen before we boarded. Pilot gave no updates other than we had to hold, attendants did speak to the crew, but when asked, said the pilot would be updating us. We on the ground in the plane waiting for over 2 hours. They did communicate that bathrooms would be open, but no other news until we left. Would have been better to be up front about status.

Good crew and flight was on time. It’s a small plane with limited overhead luggage space. They said the overhead space was full and I had to check my bag. There was still space when I got on. Waiting for my checked luggage added 30 minutes to my trip. Not the end of the world but also not great.

Flight was delayed. Not much information on when the flight would take off. Eventually we were told it was maintenance. App was not giving updates.

Flight was on time and there was an empty seat next to me. That makes for a good flight!

There's no seats that lean back with little leg space i wad uncomfortable the entire flight. Your charges for extra baggage is despicable and costly!!

Remind customers of the need to have passport or new ID for boarding.

Flight was canceled. Most upsetting was message from Kayak, stating that the flight was canceled and click with Kayak for details regarding rebook, refund details. THERE'S NO INFORMATION PROVIDED BY KAYAK EXCEPT THAT FLIGHT IS CANCELED. AND NOW THIS SURVEY TO FIND OUT HOW WAS THE FLIGHT !!!!!!!

The flight never took off and we spent 7 hours at the airport

Gate not determined until I got to the airport - hard to plan the trip to the airport.

Our flight was canceled. I will never use Kayak nor Frontier for travel again. The entire experience was a headache.

Frontier.. nickel and dime add-ons. Flight late, on time, late again, last minute gate change, arrival gate required a shuttle to the terminal. They sure keep you guessing.. if you like a little chaos and airport anxiety, this is the airline for you!

This is my second time flying with Frontier. My current experience was very favorable. The staff from the gate to the plane was friendly, warm and professional. The food options lacked in my opinion. This area needs some attention in my opinion.

There was no food and no entertainment, so I'm not sure why these are even in the survey, as my understanding is frontier does not ever offer food without a few, not even a snack, and there are no screens so unless the flight safety talk is our entertainment why ask how we liked it?. One of the flight attendants say in the back of the plane as people filed in to their seats, yelling orders about where to put baggage and telling people to hurry up. It was the least professional experience I've ever had on a flight.

Very well recently! Frontier is improving and less harrassing customer on luggages! Positive!

Everything you need to know for your flight from St. Louis to Washington, D.C.

Other airlines flying from St. Louis to Washington, D.C.

Flights from the other most popular airlines that fly from St. Louis to Washington, D.C. according to KAYAK users. Prices are the lowest found on KAYAK over the last 7 days. Price and availability are not guaranteed.

Compare transportation modes for St. Louis to Washington, D.C.

Transportation modeAverage priceAverage duration
Flights$5601h 55m
Buses$20721h 00m