STL - WAS

$63 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 5/20. 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
$124
Typical prices: $476-$320
Frontier
Tue 5/26Tue 6/2
STL - BWI • 1 stop
Cheapest non-stop
$265
Typical prices: $429-$279
Southwest
Thu 5/21Mon 5/25
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 $124 (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 05m
Direct flights
Direct flights
+1
+1
Direct flights
Direct flights
+1
Top routes
Cheapest • 10% average savings
Most popular
Insights
Insights
Insights
Insights
Top layover airports
Cheapest • Avg $169 (round-trip)
Shortest trip • 3h 59m (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 44% compared to booking last minute.
Insights
Insights
Insights
Insights
When to travel
Cheapest • 38% 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 26 - Tue, Jun 2
Frontier Logo
6:33 pm - 7:43 am
STL
-
BWI
12h 10m
1 stop
Frontier Logo
8:52 am - 5:33 pm
BWI
-
STL
9h 41m
1 stop
$124Frontier
Tue, May 26 - Tue, Jun 2
Frontier Logo
6:33 pm - 7:43 am
STL
-
BWI
12h 10m
1 stop
Frontier Logo
8:52 am - 5:33 pm
BWI
-
STL
9h 41m
1 stop
$126Frontier
Wed, Jun 3 - Sun, Jun 7
Frontier Logo
5:27 pm - 7:43 am
STL
-
BWI
13h 16m
1 stop
Frontier Logo
9:43 pm - 8:55 am
BWI
-
STL
12h 12m
1 stop
$127Frontier
Tue, May 19 - Tue, Jun 9
Southwest Logo
1:45 pm - 7:10 pm
STL
-
DCA
4h 25m
1 stop
Southwest Logo
11:45 am - 2:50 pm
DCA
-
STL
4h 05m
1 stop
$252Southwest
Tue, May 19 - Wed, Jun 3
United Airlines Logo
7:45 am - 2:14 pm
STL
-
DCA
5h 29m
1 stop
United Airlines Logo
11:57 am - 3:46 pm
DCA
-
STL
4h 49m
1 stop
$257United Airlines
Wed, Jun 24 - Sat, Jun 27
American Airlines Logo
6:00 am - 12:19 pm
STL
-
DCA
5h 19m
1 stop
American Airlines Logo
5:45 pm - 7:19 pm
DCA
-
STL
2h 34mnonstop
$260American Airlines
Wed, May 27 - Mon, Jun 1
American Airlines Logo
9:23 am - 2:57 pm
STL
-
DCA
4h 34m
1 stop
American Airlines Logo
8:00 pm - 9:29 pm
DCA
-
STL
2h 29mnonstop
$261American Airlines
Thu, May 21 - Mon, May 25
Southwest Logo
1:20 pm - 4:20 pm
STL
-
DCA
2h 00mnonstop
Southwest Logo
8:00 am - 9:20 am
DCA
-
STL
2h 20mnonstop
$265Southwest
Tue, May 19 - Sat, May 23
United Airlines Logo
8:45 am - 11:55 am
STL
-
IAD
2h 10mnonstop
United Airlines Logo
5:55 pm - 7:26 pm
IAD
-
STL
2h 31mnonstop
$265United Airlines
Wed, May 27 - Mon, Jun 1
Delta Logo
6:04 pm - 10:59 pm
STL
-
DCA
3h 55m
1 stop
Delta Logo
5:28 pm - 9:09 pm
DCA
-
STL
4h 41m
1 stop
$271Delta
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 $261 on the route between St. Louis (STL) and Washington, D.C. Reagan-National Airport (DCA). Over the past month, this route was, on average, 10% 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 Saturday, 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 $67 (return) on average. On the other hand, the most expensive months are June and September, where the average cost of round-trip tickets is $172 and $151 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.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 2 stops layover the cheapest option at $377 on average.

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 44% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 14 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$63
Best time to beat the crowds but there is an average 16% increase in price.
Most popular time to fly and prices are also 5% lower on average.
Flight from St. Louis to Washington Dulles Airport

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 $63 for a one-way ticket and $124 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.?

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

  • 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 $331 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 $350 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 $270 or less one-way and $425 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 4314 reviews
7.5Entertainment
7.0Food
8.0Comfort
8.1Boarding
8.6Crew
Airline reviews

The entire experience from boarding to landing was amazing! The crew were very friendly. Will definitely be back.

10.0 Excellentlarry, Apr 2026
LGB - PHX
Read more Southwest reviews

The entire experience from boarding to landing was amazing! The crew were very friendly. Will definitely be back.

no service at all due to turbulence. they should've at least given us snacks, there were only 10 people on the entire flight.

First time I've had to use the disabled accommodations. And I could not have had a better experience with Southwest, i was having trouble getting from one terminal to another due to my heart failure. And the next thing I know a Southwest agent had made sure. I had a wheelchair at all my flights. Can't thank them enough.

Delayed flight, lack of information, boarding process is a mess as is the carryon luggage causing issues when leaving the plane….just a poor experience.

Comfortable. Easy. No problems. Just wish they had gf options for snacks.

The crew was very kind and made going to Hawaii relaxing and fun to look forward to! Thank you Southwest for a pleasant flight!

This leg was much better, but we did have to have a 3 hour lay o er after coming from a very exhausting hiccup with our flight from BNA to Den

We waited in the airplane for over 45 min for a southwest employee to make the flight. This cause over half the plane to miss their connecting flight in Denver. When we confronted the desk upon arrival, they told us the only flight they had was the next day leaving at 8:50 pm!!! Or they offered to get us to Burbank or LA, but after that we were on our own to get back to Santa Barbara. I paid for a flight from sba to bna bna to sba. My re entry into mom mode has been 💯 rough because of southwest mistake with my flight. And now I’m leaving to Reno tomorrow for a vballl tournament and just discovered that my leg in Vegas has me and my 3 kids on a stand by flight even though I had booked these ticket last year November!! Do better southwest!

Southwest is kind of a slum airline. It’s gotten more expensive over the years for less and less service. I am a Southwest Chase Visa card holder and was forced to choose a seat in the 26th row in the middle seat. However my wife who is a rewards member but doesn’t hold a card or anything else, gets randomly assigned a normally paid seat in row 6! How does that work?

For the first time in a long time, the Wi-Fi actually worked the entire flight! The flight crew was amazing as usual.

The agent at check in and at the gate were less than thrilled to be at work. I'm not a fan of Kayak's placement on the plane. I got put in the middle seat and none of my preferences were used.

In ATL they have two sets of departure screens. Follow what is on your airline's departure board - the ATL Airport Authority departure board had completely incorrect details about the gate assignment for my flight, which would have made me miss boarding.

Flight was delayed it was hot while sitting on the plane, one engine was working on the plane until they had to do some jimmy rigging down the runway in order for the other engine to charge up. It was ridiculous

The flight was very good and the staff was very friendly and helpful!

The only thing I would say is we tried to get on a standby earlier flight, but with our fair we couldn’t. That seems senseless to leave with open seats..

Very easy to use and convenient, you can perform any action within the same portal

In a world of delays, Delta was on time both ways! Boarding was fast and efficient. Staff was friendly. AND wifi worked.

WiFi didn’t work. Flight delayed 3 hours Crew members were illiterate Seat lean back did not work.

Flight was delayed, we could have been notified earlier and in a consistent manner. App was not refreshing for another passenger to get the latest flight status. We could have stayed and waited at the hotel instead of waiting at the airport had we known the flight was going to delayed for more than 5 hours. The toilet is too tight, and needs to be cleaned more frequently (every hour). The entertainment screen froze, the touch screen not responding to touch. We were upgraded to comfort, it is more comfortable than regular economy seats.

This wasn't my experience with Delta. It was just the Pegasus flight. Seats were very hard. Staff was kinda rough. Not very nice. Charged me for snacks. For a 4 hour flight I would've expected more.

The airplane was an old model, the overhead didn’t have enough room for people’s items and made boarding and boarding disappointing and stressful. Crew allowed passengers to bring more than the permitted baggage sizes.

American delayed the flight for a crew rest period. The delay occurred late in the evening - the earliest i can find is 10:20 pm. With a 6 am flight anyone on the flight would have already have been asleep (unless you are insane, a vampire or on drugs) and at least for me i was already on the way to the airport at 445 am the next morning when i discovered they delayed the flight until 9 am. Given the incoming flight was in the air at 6 pm the evening before this should have been figured out a lot more timely that was there only crew to use. Just frustrating given there is no consideration for customer experience anymore in flying.

It was great. Smooth flight, comfortable, left on time and landed on time.

Horrible experience upon landing. Probably more due to DCA utter incompetence than AA.

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

Plane was hot and miserable and the crew was rude!

12 hour delay required getting on and off plane 3 times - would have at least liked to have been offered a snack or drink

They didn’t offer a water, even after I asked

They switched our terminal 3 times and we were delayed for four plus hours!!!

It was an early flight and most people napped/slept and the crew let us which was nice.

The crew acted like they had never done this and kept barking passive aggressive orders at people. + the security line + the delay + sitting on the tarmac for 2 hours + none of the apps or signage updating with correct times

More inflight connection. And leg space is horrible. And the paying for baggage I'd ridiculous!!!

My flight was originally from SAT to MCO connecting from MCO to ORD. We got diverted to ATL and than Frontier staff there was sooo un helpful first they said they couldn’t give us any accommodation since our flight first got delayed that cancelled and now it’s 221am and I am still in ATL since they said they need to create a new flight my final destination is ORD and I have been delayed twice and cancelled. With no real help the frontier app didn’t work no email updates over all such a horrible experience

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.

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.