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Cheap flights from St. Louis to Washington, D.C. from $52

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from St. Louis to Washington, D.C. departing on 2/3. 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 St. Louis to Washington, D.C.

Cheap round-trip flights

Enter your travel dates to find the best prices.
Multiple Airlines Logo
5:42 pm - 4:42 pmSTL-BWI
22h 00m1 stop
Multiple Airlines Logo
4:44 pm - 11:33 pmBWI-STL
7h 49m1 stop
$130Multiple Airlines
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Wed, Jan 21 - Sat, Jan 24
Multiple Airlines Logo
5:11 pm - 11:17 amSTL-BWI
17h 06m1 stop
Multiple Airlines Logo
1:02 pm - 10:33 pmBWI-STL
10h 31m1 stop
$136Multiple Airlines
Find Deal
Fri, Jan 9 - Mon, Jan 12
Frontier Logo
3:30 pm - 7:42 amSTL-BWI
15h 12m1 stop
Frontier Logo
9:43 pm - 8:59 amBWI-STL
12h 16m1 stop
$147Frontier
Find Deal
Wed, Dec 10 - Sun, Dec 14
Frontier Logo
3:43 pm - 12:29 amSTL-BWI
7h 46m1 stop
Frontier Logo
8:06 am - 4:05 pmBWI-STL
8h 59m1 stop
$162Frontier
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Thu, Jan 8 - Mon, Jan 12
Multiple Airlines Logo
11:18 am - 11:47 pmSTL-BWI
11h 29m1 stop
Multiple Airlines Logo
9:55 pm - 9:21 amBWI-STL
12h 26m1 stop
$165Multiple Airlines
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Fri, Jan 23 - Sun, Jan 25
Frontier Logo
7:43 pm - 7:44 amSTL-BWI
35h 01m2 stops
Frontier Logo
9:55 pm - 9:21 amBWI-STL
12h 26m1 stop
$167Frontier
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Sat, Jan 10 - Sun, Jan 25
Southwest Logo
7:50 am - 12:50 pmSTL-DCA
4h 00m1 stop
Southwest Logo
10:45 am - 5:35 pmDCA-STL
7h 50m2 stops
$225Southwest
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Sat, Feb 14 - Tue, Feb 17
American Airlines Logo
9:54 am - 12:59 pmSTL-DCA
2h 05mnonstop
American Airlines Logo
7:40 am - 9:24 amDCA-STL
2h 44mnonstop
$235American Airlines
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Wed, Jan 7 - Sat, Jan 10
American Airlines Logo
3:54 pm - 11:34 pmSTL-DCA
6h 40m1 stop
American Airlines Logo
7:40 am - 9:24 amDCA-STL
2h 44mnonstop
$245American Airlines
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Wed, Jan 7 - Sat, Jan 10
Southwest Logo
1:05 pm - 4:00 pmSTL-DCA
1h 55mnonstop
Southwest Logo
12:00 pm - 1:35 pmDCA-STL
2h 35mnonstop
$249Southwest
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Tue, Jan 13 - Sun, Jan 18

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

Our best United Airlines deals on St. Louis to Washington, D.C. flight tickets
United Airlines
Dec 25
STL8:15 amLambert-St Louis
2h 09m
IAD11:24 amWashington, D.C. Dulles Intl
Dec 31
IAD5:50 pmWashington, D.C. Dulles Intl
2h 32m
STL7:22 pmLambert-St Louis
$263
Find similar
United Airlines
Dec 13
STL8:00 amLambert-St Louis
4h 50m
1 stop
BWI1:50 pmBaltimore/Washington
Dec 13
BWI5:18 pmBaltimore/Washington
6h 27m
1 stop
STL10:45 pmLambert-St Louis
$481
Find similar
United Airlines
Dec 5
STL8:00 amLambert-St Louis
4h 50m
1 stop
BWI1:50 pmBaltimore/Washington
Dec 5
BWI5:18 pmBaltimore/Washington
5h 22m
1 stop
STL9:40 pmLambert-St Louis
$613
Find similar

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

Our best Delta deals on St. Louis to Washington, D.C. flight tickets
Delta
Jan 2
STL6:29 amLambert-St Louis
4h 23m
1 stop
IAD11:52 amWashington, D.C. Dulles Intl
Jan 7
IAD12:29 pmWashington, D.C. Dulles Intl
5h 08m
1 stop
STL4:37 pmLambert-St Louis
$265
Find similar
Delta
Jan 13
STL1:18 pmLambert-St Louis
7h 05m
1 stop
DCA9:23 pmWashington, D.C. Reagan-National
Jan 18
DCA7:00 amWashington, D.C. Reagan-National
5h 05m
1 stop
STL11:05 amLambert-St Louis
$269
Find similar
Delta
Dec 24
STL5:55 pmLambert-St Louis
3h 55m
1 stop
DCA10:50 pmWashington, D.C. Reagan-National
Dec 31
DCA7:20 amWashington, D.C. Reagan-National
6h 01m
1 stop
STL12:21 pmLambert-St Louis
$283
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momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Washington, D.C. 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 December 1, 2025.
Use the filters below to find and compare flights from St. Louis to Washington, D.C. that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Wed 1/21

5:42 pm-4:42 pm

1 stop22h 00m

Baltimore/Washington

Sat 1/24

4:44 pm-11:33 pm

1 stop7h 49m

$130

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Fri 1/9

5:11 pm-11:17 am

1 stop17h 06m

Baltimore/Washington

Mon 1/12

1:02 pm-10:33 pm

1 stop10h 31m

$136

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Wed 12/10

3:30 pm-7:42 am

1 stop15h 12m

Baltimore/Washington

Sun 12/14

9:43 pm-8:59 am

1 stop12h 16m

$147

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Thu 1/8

3:43 pm-12:29 am

1 stop7h 46m

Baltimore/Washington

Mon 1/12

8:06 am-4:05 pm

1 stop8h 59m

$162

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Fri 1/23

11:18 am-11:47 pm

1 stop11h 29m

Baltimore/Washington

Sun 1/25

9:55 pm-9:21 am

1 stop12h 26m

$165

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Sat 1/10

7:43 pm-7:44 am

2 stops35h 01m

Baltimore/Washington

Sun 1/25

9:55 pm-9:21 am

1 stop12h 26m

$167

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Sat 2/14

7:50 am-12:50 pm

1 stop4h 00m

Washington, D.C. Reagan-National

Tue 2/17

10:45 am-5:35 pm

2 stops7h 50m

$225

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 1/7

9:54 am-12:59 pm

Nonstop2h 05m

Washington, D.C. Reagan-National

Sat 1/10

7:40 am-9:24 am

Nonstop2h 44m

$235

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 1/7

3:54 pm-11:34 pm

1 stop6h 40m

Washington, D.C. Reagan-National

Sat 1/10

7:40 am-9:24 am

Nonstop2h 44m

$245

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Tue 1/13

1:05 pm-4:00 pm

Nonstop1h 55m

Washington, D.C. Reagan-National

Sun 1/18

12:00 pm-1:35 pm

Nonstop2h 35m

$249

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 Washington, D.C. from

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

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 cheapest month to fly to Washington, D.C.?

The month of August is, on average, the cheapest month to fly to Washington, D.C. from St. Louis, with most prices found around $229. If you’re not able to fly to Washington, D.C. in August, then October is your next best option. Flight prices from St. Louis to Washington, D.C. during October average around $255.

What is the cheapest day to depart on your flight to Washington, D.C.?

On average, the least expensive day to fly to Washington, D.C. from St. Louis is on a Friday. momondo users have found tickets for Friday departures for as low as $359. However, this price may fluctuate depending on the airline, the season, and holidays. When flying out on a Sunday, the most expensive travel day of the week, you can expect to see flight prices from St. Louis to Washington, D.C. for around $502.

What is the cheapest time of day to depart on your flight to Washington, D.C.?

In the evening is the cheapest time of day to fly from St. Louis to Washington, D.C. when you can find flight prices for as low as $291. Flying to Washington, D.C. in the evening is an ideal time because this is during off-peak travel hours. Try not to purchase tickets at noon because they tend to be around $923. Of course, these prices can vary depending on the time of year and what airport you fly to.

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

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

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

You are more likely to see cheaper flights to Washington, D.C. from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Washington, D.C. for around $371 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Washington, D.C. from St. Louis for as low as $236 on momondo.

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

There are 4 cabin classes available to choose from on Lambert-St Louis to Washington, D.C. 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 St. Louis to Washington, D.C. flights?

You could potentially save up to 27% on your flight if you consider stops on a St. Louis to Washington, D.C. flight.

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

As of December 2025, prices for St. Louis to Washington, D.C. flights are approximately 13% more expensive when compared to flights at the same time last year.

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

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

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

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

Best Price Found

$173

Fastest flight time

1h 55m

Direct flights

Every day

Airports in Washington, D.C.

2 airports
The best one-way flight to Washington, D.C. from St. Louis in the past 72 hours is $173. The best round-trip flight deal from St. Louis to Washington, D.C. found on momondo in the last 72 hours is $304.
The fastest flight from St. Louis to Washington, D.C. takes 1h 55m
Direct flights go from St. Louis to Washington, D.C. every day.
There are 2 airports near Washington, D.C.: Washington, D.C. Reagan-National (DCA), Baltimore/Washington (BWI)
Search flight deals

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

    A flight from Lambert-St Louis to Washington, D.C. will travel around 708.3 mi. By plane, this route typically takes 1h 55m.

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

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

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

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

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Lambert-St Louis Airport to Washington, D.C..

  • What documentation or ID do you need to fly to Washington, D.C.?

    The travel and health documents required for your trip to Washington, D.C. can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Washington, D.C.. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

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

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

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

Compare and see reviews for airlines that fly from St. Louis to Washington, D.C. with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $113Free CancellationRating
5.8
3,094 reviews
Search Frontier flights
DeltaPriceFrom $124Free CancellationRating
7.9
8,010 reviews
Search Delta flights
American AirlinesPriceFrom $177Free CancellationRating
7.2
11,041 reviews
Search American Airlines flights
SouthwestPriceFrom $197Free CancellationRating
8.0
4,253 reviews
Search Southwest flights
United AirlinesPriceFrom $262Free CancellationRating
7.4
9,065 reviews
Search United Airlines flights

  • Southwest Flights From St. Louis to Washington, D.C.

    Southwest operates around 4 flights from St. Louis to Washington, D.C. every week. The average price of these flights found in the last 72 hours has been $341, but momondo users have found Southwest deals from St. Louis to Washington, D.C. from as low as $197 round-trip. Southwest has been scored 8.0/10 in 4,253 reviews.

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

    The best United Airlines deal for St. Louis to Washington, D.C. flight tickets found on momondo in the last 72 hours was $262, round-trip. It should be noted that an average United Airlines flight deal for this route in this time was higher, at $457 round-trip. United Airlines operates 8 flights out of St. Louis into Washington, D.C. in an average week, so prices vary by time and availability. 9,065 United Airlines reviews by users on momondo have scored the airline at 7.4/10.

Traveling to a place near Washington, D.C.?

Book flights to Washington, D.C. if you plan to visit one of these locations
Alexandria
National Harbor
Gettysburg
Arlington
Woodbridge
Waldorf
Tysons
Laurel
Colonial Beach
Silver Spring
Fredericksburg
Towson
Rockville
Reston
Manassas
Gaithersburg
Fairfax
Glen Burnie
Linthicum Heights
Springfield

Why use momondo?

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

momondo collates all your flight options in one place and lets you filter them to find the perfect flight from St. Louis to Washington, D.C.. momondo saves you time and could save you money on your trip.

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

Yes. All flights to Washington, D.C. from St. Louis on momondo can be compared and filtered by various policies on offer, including flexible booking.

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

momondo provides multiple filters to help you find the best flight to Washington, D.C. from St. Louis. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

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

Of course. momondo tracks the price of St. Louis to Washington, D.C. flights. All you need is a valid email address and we will do the rest; it is that quick and easy.

An easier way to manage your Washington, D.C. trip

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Find better results for your trip to the United States

Fly into one of these airports located in Washington, D.C.

Airports listed have a maximum distance of 22.4 mi from Washington, D.C.
Washington, D.C. Reagan-National Airport
Washington, D.C. Dulles Intl Airport