Cheap flights from Washington, D.C. to St. Louis from $63

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Washington, D.C. to St. Louis departing on 5/19. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Find the cheapest flights from Washington, D.C. to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
9:13 pm - 8:55 am
BWI
-
STL
12h 42m
1 stop
Frontier Logo
5:27 pm - 7:43 am
STL
-
BWI
13h 16m
1 stop
$127Frontier
Tue, May 5 - Wed, May 13
Frontier Logo
9:13 pm - 4:54 pm
BWI
-
STL
20h 41m
1 stop
Frontier Logo
5:27 pm - 7:43 am
STL
-
BWI
13h 16m
1 stop
$128Frontier
Wed, May 6 - Wed, May 13
Frontier Logo
9:13 pm - 8:55 am
BWI
-
STL
12h 42m
1 stop
Frontier Logo
5:27 pm - 7:43 am
STL
-
BWI
13h 16m
1 stop
$129Frontier
Tue, May 5 - Mon, May 11
United Airlines Logo
5:50 pm - 7:27 pm
IAD
-
STL
2h 37mnonstop
United Airlines Logo
7:45 am - 2:03 pm
STL
-
IAD
5h 18m
1 stop
$267United Airlines
Wed, May 6 - Wed, May 13
American Airlines Logo
1:06 pm - 7:00 pm
IAD
-
STL
6h 54m
1 stop
American Airlines Logo
6:12 pm - 12:13 am
STL
-
IAD
5h 01m
1 stop
$271American Airlines
Thu, May 28 - Tue, Jun 2
Delta Logo
6:00 am - 12:22 pm
DCA
-
STL
7h 22m
1 stop
Delta Logo
9:30 am - 4:20 pm
STL
-
DCA
5h 50m
1 stop
$271Delta
Tue, May 19 - Thu, May 21
Southwest Logo
6:35 pm - 11:55 pm
DCA
-
STL
6h 20m
1 stop
Southwest Logo
3:45 pm - 6:45 pm
STL
-
DCA
2h 00mnonstop
$275Southwest
Mon, May 4 - Mon, May 11
United Airlines Logo
9:00 am - 10:31 am
IAD
-
STL
2h 31mnonstop
United Airlines Logo
11:15 am - 7:23 pm
STL
-
IAD
7h 08m
1 stop
$275United Airlines
Sat, Apr 25 - Mon, Apr 27
Southwest Logo
6:35 pm - 11:55 pm
DCA
-
STL
6h 20m
1 stop
Southwest Logo
2:10 pm - 10:25 pm
STL
-
DCA
7h 15m
2 stops
$276Southwest
Mon, May 4 - Wed, May 6
Delta Logo
6:08 am - 12:22 pm
IAD
-
STL
7h 14m
1 stop
Delta Logo
5:15 pm - 12:51 am
STL
-
IAD
6h 36m
1 stop
$277Delta
Tue, May 12 - Tue, May 12

Frontier flights from Washington, D.C. to St. Louis

Our best Frontier deals on Washington, D.C. to St. Louis flight tickets
Frontier
May 5
BWI9:13 pmBaltimore/Washington
12h 42m
1 stop
STL8:55 amLambert-St Louis
May 13
STL5:27 pmLambert-St Louis
13h 16m
1 stop
BWI7:43 amBaltimore/Washington
$127
Frontier
May 6
BWI9:13 pmBaltimore/Washington
20h 41m
1 stop
STL4:54 pmLambert-St Louis
May 13
STL5:27 pmLambert-St Louis
13h 16m
1 stop
BWI7:43 amBaltimore/Washington
$128
Frontier
May 5
BWI9:13 pmBaltimore/Washington
12h 42m
1 stop
STL8:55 amLambert-St Louis
May 11
STL5:27 pmLambert-St Louis
13h 16m
1 stop
BWI7:43 amBaltimore/Washington
$129

American Airlines flights from Washington, D.C. to St. Louis

Our best American Airlines deals on Washington, D.C. to St. Louis flight tickets
American Airlines
May 28
IAD1:06 pmWashington, D.C. Dulles Intl
6h 54m
1 stop
STL7:00 pmLambert-St Louis
Jun 2
STL6:12 pmLambert-St Louis
5h 01m
1 stop
IAD12:13 amWashington, D.C. Dulles Intl
$271
American Airlines
May 12
DCA7:59 amWashington, D.C. Reagan-National
2h 26m
STL9:25 amLambert-St Louis
May 15
STL3:43 pmLambert-St Louis
2h 15m
DCA6:58 pmWashington, D.C. Reagan-National
$288
American Airlines
May 13
DCA8:12 amWashington, D.C. Reagan-National
2h 25m
STL9:37 amLambert-St Louis
May 24
STL6:00 amLambert-St Louis
2h 19m
DCA9:19 amWashington, D.C. Reagan-National
$293

momondo Fare Finder

 
Customize your flight search to find flights from Washington, D.C. 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, momondo users made 832,500 searches. Data last updated April 7, 2026.
Use the filters below to find and compare flights from Washington, D.C. to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Tue 5/5

9:13 pm-8:55 am

1 stop12h 42m

Lambert-St Louis

Wed 5/13

5:27 pm-7:43 am

1 stop13h 16m

$127

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Wed 5/6

9:13 pm-4:54 pm

1 stop20h 41m

Lambert-St Louis

Wed 5/13

5:27 pm-7:43 am

1 stop13h 16m

$128

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Tue 5/5

9:13 pm-8:55 am

1 stop12h 42m

Lambert-St Louis

Mon 5/11

5:27 pm-7:43 am

1 stop13h 16m

$129
Quickest round-trip

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Wed 5/6

5:50 pm-7:27 pm

Nonstop2h 37m

Lambert-St Louis

Wed 5/13

7:45 am-2:03 pm

1 stop5h 18m

$267

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Thu 5/28

1:06 pm-7:00 pm

1 stop6h 54m

Lambert-St Louis

Tue 6/2

6:12 pm-12:13 am

1 stop5h 01m

$271

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Tue 5/19

6:00 am-12:22 pm

1 stop7h 22m

Lambert-St Louis

Thu 5/21

9:30 am-4:20 pm

1 stop5h 50m

$271

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Mon 5/4

6:35 pm-11:55 pm

1 stop6h 20m

Lambert-St Louis

Mon 5/11

3:45 pm-6:45 pm

Nonstop2h 00m

$275

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Sat 4/25

9:00 am-10:31 am

Nonstop2h 31m

Lambert-St Louis

Mon 4/27

11:15 am-7:23 pm

1 stop7h 08m

$275

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Mon 5/4

6:35 pm-11:55 pm

1 stop6h 20m

Lambert-St Louis

Wed 5/6

2:10 pm-10:25 pm

2 stops7h 15m

$276

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Tue 5/12

6:08 am-12:22 pm

1 stop7h 14m

Lambert-St Louis

Tue 5/12

5:15 pm-12:51 am

1 stop6h 36m

$277

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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See travel insights to St. Louis from

How to get the cheapest flight ticket from Washington, D.C. to St. Louis

Look no further. We've gone through all the searches for this route on momondo so you have the important information and insights to find the cheapest flight ticket for your trip

What is the typical price of a round-trip flight between Washington, D.C. and St. Louis?

What is the cheapest month to fly to St. Louis?

In general, August is the cheapest month to fly from Washington, D.C. to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $277. The month of September is another great option to travel to St. Louis, with average flight prices from Washington, D.C. averaging around $295.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Tuesday when prices can be found for as low as $329. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $401. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Washington, D.C. in the evening is the least expensive time of day to depart. momondo users have found prices as low as $325 when looking at flights departing in the evening. In the afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $388 per ticket.

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

Fly from Washington, D.C. Reagan-National to Lambert-St Louis for the best Washington, D.C. - Lambert-St Louis flight prices

What cabin class options are available on Washington, D.C. to Lambert-St Louis flights?

There are 4 cabin classes available to choose from on Washington, D.C. to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

Can stopping save me money on Washington, D.C. to St. Louis flights?

You could potentially save up to 11% on your flight if you consider stops on a Washington, D.C. to St. Louis flight.

How have Washington, D.C. to St. Louis flight prices changed over time?

As of April 2026, prices for Washington, D.C. to St. Louis flights are approximately 114% more expensive when compared to flights at the same time last year.

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

Are you open to changing your travel dates? Check out the ideal times to fly from Washington, D.C. to St. Louis according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

Cheap Washington, D.C. to St. Louis (WAS to STL) flight deals and tips

Find info about flight duration, direct flights, and airports for your flight from Washington, D.C. to St. Louis

Best Price Found

$174

Fastest flight time

2h 10m

Direct flights

Every day

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Washington, D.C. in the past 72 hours is $174. The best round-trip flight deal from Washington, D.C. to St. Louis found on momondo in the last 72 hours is $302.
The fastest flight from Washington, D.C. to St. Louis takes 2h 10m
Direct flights go from Washington, D.C. to St. Louis every day.
There is 1 airport in St. Louis. From Washington, D.C. there are direct flights to Lambert-St Louis (STL).

Frequently asked questions about flying from Washington, D.C. to St. Louis

  • How far is Washington, D.C. to Lambert-St Louis by plane?

    There are 708.3 mi between Washington, D.C. and Lambert-St Louis. 2h 10m is a normal flight duration for this route.

  • When did momondo last update prices for flights from Washington, D.C. to Lambert-St Louis Airport?

    Prices for flights from Washington, D.C. to Lambert-St Louis Airport are updated daily.

  • How many operators does momondo search for flights from Washington, D.C. to Lambert-St Louis Airport?

  • How old do you have to be to fly from Washington, D.C. to Lambert-St Louis Airport?

    The minimum age for a child to fly alone is five, but airlines offering an unaccompanied minor (UNMR) service may have their age restrictions, such as regulations concerning flight duration, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Washington, D.C. to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The required travel and health documents for your Lambert-St Louis Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Lambert-St Louis Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

  • What is the most popular plane model from Washington, D.C. to St. Louis?

  • What is the most popular airline from Washington, D.C. to St. Louis?

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

Compare and see reviews for airlines that fly from Washington, D.C. to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $78Free CancellationRating
5.7
3,000 reviews
Search Frontier flights
DeltaPriceFrom $124Free CancellationRating
7.9
8,387 reviews
Search Delta flights
American AirlinesPriceFrom $167Free CancellationRating
7.1
11,546 reviews
Search American Airlines flights
SouthwestPriceFrom $188Free CancellationRating
8.0
4,338 reviews
Search Southwest flights
United AirlinesPriceFrom $269Free CancellationRating
7.4
9,548 reviews
Search United Airlines flights
  • Southwest Flights From Washington, D.C. to St. Louis

    Southwest operates around 13 flights from Washington, D.C. to St. Louis every week. The average price of these flights found in the last 72 hours has been $373, but momondo users have found Southwest deals from Washington, D.C. to St. Louis from as low as $188 round-trip. Southwest has been scored 8.0/10 in 4,338 reviews.

  • United Airlines Flights From Washington, D.C. to St. Louis

    United Airlines (7.4/10 from 9,548 reviews) operates around 13 flights from Washington, D.C. to St. Louis in any given week. The average United Airlines airfare for this route is around $503, with deals from around $269 rare but found on momondo. Referenced prices are for round-trip Washington, D.C. to St. Louis flight searches in the last 72 hours.

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Hermann
Fairview Heights
Maryland Heights
O'Fallon
Florissant
St. Peters
Collinsville
Wentzville
Alton
Fenton
Farmington
Clayton
Festus
Eureka
Edwardsville
Litchfield
Shrewsbury
Grafton

Why use momondo?

Why should I use momondo to find a flight deal from Washington, D.C. to St. Louis?

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to St. Louis from Washington, D.C..

Can I find flights from Washington, D.C. to St. Louis with flexible booking policies on momondo?

Yes. momondo allows you to filter the results for Washington, D.C. to St. Louis flights to just show those with flexible booking policies.

How can momondo help me find flights from Washington, D.C. to St. Louis?

momondo helps you find the best flight between Washington, D.C. and St. Louis by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

I’m not ready to book a flight from Washington, D.C. to St. Louis right now. Can momondo alert me if prices change?

If you are simply researching potential flights to St. Louis, momondo offers a useful price alert feature which will track prices for flights to St. Louis from Washington, D.C. and alert you when they change.

An easier way to manage your St. Louis trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

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1 adult
Thu 5/7
Thu 5/14

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