Cheap flights from Washington, D.C. to St. Louis from $61

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 3/9. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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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
3:19 pm - 10:32 am
BWI
-
STL
20h 13m
1 stop
Frontier Logo
8:13 pm - 8:12 am
STL
-
BWI
10h 59m
1 stop
$137Frontier
Mon, Mar 23 - Wed, Apr 15
Frontier Logo
6:00 pm - 6:50 am
BWI
-
STL
13h 50m
1 stop
Frontier Logo
8:13 pm - 8:12 am
STL
-
BWI
10h 59m
1 stop
$151Frontier
Tue, May 12 - Fri, May 15
Frontier Logo
3:19 pm - 10:32 am
BWI
-
STL
20h 13m
1 stop
Frontier Logo
11:21 am - 12:41 am
STL
-
BWI
12h 20m
1 stop
$158Frontier
Mon, Mar 23 - Thu, Mar 26
Frontier Logo
5:35 pm - 11:19 pm
BWI
-
STL
6h 44m
1 stop
Frontier Logo
8:13 pm - 8:12 am
STL
-
BWI
10h 59m
1 stop
$160Frontier
Fri, May 15 - Mon, May 18
American Airlines Logo
7:30 am - 9:06 am
DCA
-
STL
2h 36mnonstop
American Airlines Logo
6:00 am - 9:12 am
STL
-
DCA
2h 12mnonstop
$270American Airlines
Mon, Mar 23 - Thu, Mar 26
American Airlines Logo
8:00 am - 9:26 am
DCA
-
STL
2h 26mnonstop
American Airlines Logo
6:05 am - 9:15 am
STL
-
DCA
2h 10mnonstop
$271American Airlines
Thu, Apr 9 - Fri, Apr 10
Southwest Logo
6:50 pm - 10:55 pm
DCA
-
STL
5h 05m
1 stop
Southwest Logo
9:35 pm - 8:15 am
STL
-
DCA
9h 40m
1 stop
$272Southwest
Sat, Mar 14 - Sat, Mar 21
Southwest Logo
8:00 am - 9:30 am
DCA
-
STL
2h 30mnonstop
Southwest Logo
12:40 pm - 8:45 pm
STL
-
DCA
7h 05m
2 stops
$273Southwest
Thu, Apr 2 - Tue, Apr 7
United Airlines Logo
5:41 pm - 11:57 pm
IAD
-
STL
7h 16m
1 stop
United Airlines Logo
8:30 am - 11:43 am
STL
-
IAD
2h 13mnonstop
$274United Airlines
Tue, Mar 31 - Wed, Apr 1
Delta Logo
10:11 am - 4:10 pm
IAD
-
STL
6h 59m
1 stop
Delta Logo
7:15 am - 2:04 pm
STL
-
IAD
5h 49m
1 stop
$280Delta
Tue, May 19 - Wed, May 27

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

Our best Frontier deals on Washington, D.C. to St. Louis flight tickets
Frontier
Mar 23
BWI3:19 pmBaltimore/Washington
20h 13m
1 stop
STL10:32 amLambert-St Louis
Apr 15
STL8:13 pmLambert-St Louis
10h 59m
1 stop
BWI8:12 amBaltimore/Washington
$137
Frontier
May 12
BWI6:00 pmBaltimore/Washington
13h 50m
1 stop
STL6:50 amLambert-St Louis
May 15
STL8:13 pmLambert-St Louis
10h 59m
1 stop
BWI8:12 amBaltimore/Washington
$151
Frontier
Mar 23
BWI3:19 pmBaltimore/Washington
20h 13m
1 stop
STL10:32 amLambert-St Louis
Mar 26
STL11:21 amLambert-St Louis
12h 20m
1 stop
BWI12:41 amBaltimore/Washington
$158

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

Our best Southwest deals on Washington, D.C. to St. Louis flight tickets
Southwest
Mar 14
DCA6:50 pmWashington, D.C. Reagan-National
5h 05m
1 stop
STL10:55 pmLambert-St Louis
Mar 21
STL9:35 pmLambert-St Louis
9h 40m
1 stop
DCA8:15 amWashington, D.C. Reagan-National
$272
Southwest
Apr 2
DCA8:00 amWashington, D.C. Reagan-National
2h 30m
STL9:30 amLambert-St Louis
Apr 7
STL12:40 pmLambert-St Louis
7h 05m
2 stops
DCA8:45 pmWashington, D.C. Reagan-National
$273
Southwest
Mar 14
DCA8:05 amWashington, D.C. Reagan-National
2h 30m
STL9:35 amLambert-St Louis
Mar 21
STL9:35 pmLambert-St Louis
9h 40m
1 stop
DCA8:15 amWashington, D.C. Reagan-National
$274

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 February 16, 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

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Mon 3/23

3:19 pm-10:32 am

1 stop20h 13m

Lambert-St Louis

Wed 4/15

8:13 pm-8:12 am

1 stop10h 59m

$137

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Tue 5/12

6:00 pm-6:50 am

1 stop13h 50m

Lambert-St Louis

Fri 5/15

8:13 pm-8:12 am

1 stop10h 59m

$151

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Mon 3/23

3:19 pm-10:32 am

1 stop20h 13m

Lambert-St Louis

Thu 3/26

11:21 am-12:41 am

1 stop12h 20m

$158

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Fri 5/15

5:35 pm-11:19 pm

1 stop6h 44m

Lambert-St Louis

Mon 5/18

8:13 pm-8:12 am

1 stop10h 59m

$160

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Mon 3/23

7:30 am-9:06 am

Nonstop2h 36m

Lambert-St Louis

Thu 3/26

6:00 am-9:12 am

Nonstop2h 12m

$270

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Thu 4/9

8:00 am-9:26 am

Nonstop2h 26m

Lambert-St Louis

Fri 4/10

6:05 am-9:15 am

Nonstop2h 10m

$271

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Sat 3/14

6:50 pm-10:55 pm

1 stop5h 05m

Lambert-St Louis

Sat 3/21

9:35 pm-8:15 am

1 stop9h 40m

$272

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Thu 4/2

8:00 am-9:30 am

Nonstop2h 30m

Lambert-St Louis

Tue 4/7

12:40 pm-8:45 pm

2 stops7h 05m

$273

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Tue 3/31

5:41 pm-11:57 pm

1 stop7h 16m

Lambert-St Louis

Wed 4/1

8:30 am-11:43 am

Nonstop2h 13m

$274

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Tue 5/19

10:11 am-4:10 pm

1 stop6h 59m

Lambert-St Louis

Wed 5/27

7:15 am-2:04 pm

1 stop5h 49m

$280

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 $273. The month of October is another great option to travel to St. Louis, with average flight prices from Washington, D.C. averaging around $293.

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 Saturday when prices can be found for as low as $332. 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 $403. 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 $308 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 $377 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.

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

As of February 2026, prices for Washington, D.C. to St. Louis flights are approximately 47% cheaper 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

$154

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 $154. The best round-trip flight deal from Washington, D.C. to St. Louis found on momondo in the last 72 hours is $303.
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).
  • 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
3,047 reviews
Search Frontier flights
DeltaPriceFrom $124Free CancellationRating
7.9
8,204 reviews
Search Delta flights
American AirlinesPriceFrom $167Free CancellationRating
7.2
11,294 reviews
Search American Airlines flights
SouthwestPriceFrom $188Free CancellationRating
8.0
4,285 reviews
Search Southwest flights
United AirlinesPriceFrom $227Free CancellationRating
7.4
9,299 reviews
Search United Airlines flights
  • Southwest Flights From Washington, D.C. to St. Louis

    Southwest operates around 21 flights from Washington, D.C. to St. Louis every week. The average price of these flights found in the last 72 hours has been $360, 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 4,285 reviews.

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

    United Airlines (7.4/10 from 9,299 reviews) operates around 14 flights from Washington, D.C. to St. Louis in any given week. The average United Airlines airfare for this route is around $459, with deals from around $227 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
Florissant
O'Fallon
Collinsville
St. Peters
Fenton
Wentzville
Alton
Farmington
Clayton
Edwardsville
Eureka
Festus
Litchfield
Glencoe
Shrewsbury

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

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1 adult
Wed 3/18
Wed 3/25

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