Is Southwest the cheapest airline to fly with from St. Louis to Washington, D.C.?

With an average price of $305 return, Southwest is not the cheapest airline to fly from St. Louis to Washington, D.C. with. Instead, for the lowest price, our data suggests flying with Frontier, where a return flight costs $217 on average.

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

In the last 3 days, the lowest price for a flight with Southwest from St. Louis to Washington, D.C. was $236 for a return flight and $131 for a one-way flight.

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

Yes, Southwest does offer direct flights for the route, with around 4 flights per week.

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

On average, the cheapest day of the week to fly from St. Louis to Washington, D.C. with Southwest is Wednesday, when prices are around $88. The most expensive day is generally Saturday, where the average price is around $114.

What’s the cheapest month to fly from St. Louis to Washington, D.C. with Southwest?

The cheapest month for Southwest flights to Washington, D.C. from St. Louis is generally August, where plane tickets cost $114 on average. If possible, try to avoid the most expensive months of January and March, where tickets cost $278 and $312 respectively.

$110 Cheap Southwest Flights from St. Louis to Washington, D.C.

STL - WAS

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Cheap Southwest Flight Deals from St. Louis to Washington, D.C.

Here are some of the best deals found on KAYAK recently from Southwest 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.

Round-trip

One-way

Last minute

Direct

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

Fri, Nov 28 - Fri, Dec 5

5:15 am - 11:35 amSTL-BWI

5h 20m1 stop

3:00 pm - 7:25 pmBWI-STL

5h 25m1 stop

$229Southwest

Find Deal

Thu, Dec 4 - Mon, Dec 8

12:45 pm - 7:55 pmSTL-BWI

6h 10m2 stops

4:45 pm - 10:20 pmBWI-STL

6h 35m1 stop

$234Southwest

Find Deal

Fri, Dec 5 - Sat, Dec 6

12:45 pm - 7:55 pmSTL-BWI

6h 10m2 stops

10:30 am - 5:00 pmBWI-STL

7h 30m2 stops

$239Southwest

Find Deal

Wed, Dec 24 - Wed, Dec 31

3:20 pm - 6:15 pmSTL-DCA

1h 55mnonstop

12:25 pm - 1:45 pmDCA-STL

2h 20mnonstop

$259Southwest

Find Deal

Sat, Nov 22 - Mon, Nov 24

8:55 am - 11:50 amSTL-DCA

1h 55mnonstop

8:00 am - 9:20 amDCA-STL

2h 20mnonstop

$261Southwest

Find Deal

Thu, Dec 4 - Mon, Dec 8

8:45 am - 11:40 amSTL-DCA

1h 55mnonstop

6:10 pm - 7:35 pmDCA-STL

2h 25mnonstop

$263Southwest

Find Deal

Sat, Jan 24 - Tue, Jan 27

8:45 am - 1:40 pmSTL-BWI

3h 55m1 stop

7:45 am - 9:25 amBWI-STL

2h 40mnonstop

$263Southwest

Find Deal

Thu, Jan 15 - Sun, Jan 18

9:40 am - 2:55 pmSTL-DCA

4h 15m1 stop

6:45 pm - 8:15 pmDCA-STL

2h 30mnonstop

$267Southwest

Find Deal

Thu, Dec 4 - Mon, Dec 8

6:05 am - 9:05 amSTL-BWI

2h 00mnonstop

10:15 am - 1:50 pmBWI-STL

4h 35m1 stop

$267Southwest

Find Deal

Wed, Dec 17 - Thu, Dec 18

10:25 am - 5:25 pmSTL-BWI

6h 00m1 stop

4:10 pm - 7:35 pmBWI-STL

4h 25m1 stop

$268Southwest

Find Deal

Useful Info

Low season	September
High season	March
Cheapest flight	$110
Average price round-trip	$316
Good deal one-way	$186

Best time to beat the crowds with an average 8% drop in price.

Most popular time to fly with an average 30% increase in price.

Flight from St. Louis to Baltimore

(avg. price over the last 2 weeks)

or less

When to Book Flights with Southwest from St. Louis to Washington, D.C.

Average price per month

Flight prices as travel date approaches

Is Southwest the cheapest airline to fly with from St. Louis to Washington, D.C.?
With an average price of $305 return, Southwest is not the cheapest airline to fly from St. Louis to Washington, D.C. with. Instead, for the lowest price, our data suggests flying with Frontier, where a return flight costs $217 on average.
What is the cheapest Southwest flight from St. Louis to Washington, D.C.?
In the last 3 days, the lowest price for a flight with Southwest from St. Louis to Washington, D.C. was $236 for a return flight and $131 for a one-way flight.
Does Southwest fly direct to Washington, D.C. from St. Louis?
Yes, Southwest does offer direct flights for the route, with around 4 flights per week.
What’s the cheapest day of the week to fly from St. Louis to Washington, D.C. with Southwest?
On average, the cheapest day of the week to fly from St. Louis to Washington, D.C. with Southwest is Wednesday, when prices are around $88. The most expensive day is generally Saturday, where the average price is around $114.
What’s the cheapest month to fly from St. Louis to Washington, D.C. with Southwest?
The cheapest month for Southwest flights to Washington, D.C. from St. Louis is generally August, where plane tickets cost $114 on average. If possible, try to avoid the most expensive months of January and March, where tickets cost $278 and $312 respectively.

8.0

Very good4,241 verified ratings

8.0Comfort

7.5Entertainment

7.0Food

8.1Boarding

8.6Crew

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Cons -

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10.0 Wonderful

James, Oct 2025

TUS-LAS

Very good

8.0 Very good

Greg, Oct 2025

OAK-BUR

Ever since Southwest starting charging for bags, passengers don't want to pay to check their bags, so the gate agents have to beg people to check their roller bags now because there's "not enough space". This was a terrible business move by Southwest.

8.0 Very good

Margaret, Oct 2025

SAV-HOU

Full cans of soda would be nice. A choice between two snacks would be appreciated.

8.0 Very good

TODD, Oct 2025

CMH-HOU

Tried watching free movie and it kept freezing so I couldn’t finish.

10.0 Wonderful

Antonio, Oct 2025

PVD-MCO

Always reliable

10.0 Wonderful

Verified traveler, Oct 2025

MDW-BWI

All was good. I just had a hard time getting connected to the WiFi/internet during the flight

4.0 Mediocre

Mike, Oct 2025

GRR-MDW

Staff/crew very good. 4 hour delay not good.

10.0 Wonderful

Stacy, Oct 2025

SMF-DEN

Sacrament staff are always polite and helpful. Airport is easy to maneuver and boarding is straightforward.

2.0 Poor

Verified traveler, Oct 2025

DAL-LIT

Delayed 5.5 hours

10.0 Wonderful

Verified traveler, Oct 2025

BOS-BWI

Great flight. Outstanding Service. Southwest was able to put us on a direct flight to Denver when the connection could have been affected by a later arrival to Baltimore. The direct flight was less expensive that the flight with the connection in Baltimore.

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

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Cabin class types available on flights to Washington, D.C.

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STL - WAS

$110 Find Cheap Southwest Flights from St. Louis to Washington, D.C.

Search hundreds of travel sites at once for deals on Southwest flights from St. Louis to Washington, D.C.

Cheap Southwest Flight Deals from St. Louis to Washington, D.C.

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

Recent one-way Southwest flight deals from St. Louis to Washington, D.C.

Recent last minute Southwest flight deals from St. Louis to Washington, D.C.

Recent direct Southwest flight deals from St. Louis to Washington, D.C.

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When to Book Flights with Southwest from St. Louis to Washington, D.C.

FAQs for flying to Washington, D.C. with Southwest

Is Southwest the cheapest airline to fly with from St. Louis to Washington, D.C.?

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

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

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

What’s the cheapest month to fly from St. Louis to Washington, D.C. with Southwest?

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

Cabin class types available on flights to Washington, D.C.

Cabin classes available on flights to St. Louis. Prices are the lowest found on KAYAK over the last 7 days. Price and availability is not guaranteed.

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The most popular flights on KAYAK according to clicks in the last 2 weeks. Prices are the lowest found on KAYAK over the last 7 days. Price and availability is not guaranteed.

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The most popular destinations for flights with Southwest according to clicks from KAYAK users. Prices are the lowest found on KAYAK over the last 7 days. Price and availability is not guaranteed.