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Cheap flights from St. Louis to Washington, D.C. from $65

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 1/14. 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

Frontier Logo
10:49 am - 5:53 pmSTL-BWI
6h 04m1 stop
Frontier Logo
6:22 am - 3:04 pmBWI-STL
9h 42m1 stop
$143Frontier
Find Deal
Thu, Oct 2 - Mon, Oct 6
Frontier Logo
10:49 am - 5:53 pmSTL-BWI
6h 04m1 stop
Frontier Logo
6:22 am - 3:04 pmBWI-STL
9h 42m1 stop
$144Frontier
Find Deal
Thu, Sep 25 - Mon, Sep 29
American Airlines Logo
12:51 pm - 8:48 pmSTL-BWI
6h 57m1 stop
American Airlines Logo
6:13 pm - 11:54 pmBWI-STL
6h 41m1 stop
$158American Airlines
Find Deal
Tue, Oct 14 - Wed, Oct 15
American Airlines Logo
5:00 am - 10:58 amSTL-BWI
4h 58m1 stop
American Airlines Logo
8:21 pm - 12:05 amBWI-STL
4h 44m1 stop
$159American Airlines
Find Deal
Thu, Nov 20 - Fri, Nov 28
Delta Logo
6:09 pm - 11:04 pmSTL-DCA
3h 55m1 stop
Delta Logo
8:59 am - 1:00 pmDCA-STL
5h 01m1 stop
$197Delta
Find Deal
Mon, Nov 10 - Wed, Nov 19
Delta Logo
6:09 pm - 11:03 pmSTL-IAD
3h 54m1 stop
Delta Logo
12:36 pm - 4:07 pmIAD-STL
4h 31m1 stop
$197Delta
Find Deal
Mon, Nov 10 - Tue, Nov 18
United Airlines Logo
8:05 am - 11:15 amSTL-IAD
2h 10mnonstop
United Airlines Logo
6:30 am - 10:49 amIAD-STL
5h 19m1 stop
$212United Airlines
Find Deal
Sun, Oct 5 - Sun, Oct 12
United Airlines Logo
3:23 pm - 9:22 pmSTL-BWI
4h 59m1 stop
United Airlines Logo
6:29 am - 10:49 amBWI-STL
5h 20m1 stop
$217United Airlines
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Tue, Oct 21 - Thu, Oct 23
Southwest Logo
8:15 pm - 11:15 pmSTL-DCA
2h 00mnonstop
Southwest Logo
3:40 pm - 7:30 pmDCA-STL
4h 50m1 stop
$236Southwest
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Mon, Oct 13 - Mon, Oct 20
Southwest Logo
3:25 pm - 10:25 pmSTL-DCA
6h 00m1 stop
Southwest Logo
12:30 pm - 9:00 pmDCA-STL
9h 30m1 stop
$247Southwest
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Fri, Oct 10 - Sat, Oct 11

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
Oct 5
STL8:05 amLambert-St Louis
2h 10m
IAD11:15 amWashington, D.C. Dulles Intl
Oct 12
IAD6:30 amWashington, D.C. Dulles Intl
5h 19m
1 stop
STL10:49 amLambert-St Louis
$212
Find similar
United Airlines
Oct 21
STL3:23 pmLambert-St Louis
4h 59m
1 stop
BWI9:22 pmBaltimore/Washington
Oct 23
BWI6:29 amBaltimore/Washington
5h 20m
1 stop
STL10:49 amLambert-St Louis
$217
Find similar
United Airlines
Mar 10
STL3:15 pmLambert-St Louis
4h 42m
1 stop
BWI8:57 pmBaltimore/Washington
Mar 11
BWI10:45 amBaltimore/Washington
5h 36m
1 stop
STL3:21 pmLambert-St Louis
$221
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
Nov 10
STL6:09 pmLambert-St Louis
3h 54m
1 stop
IAD11:03 pmWashington, D.C. Dulles Intl
Nov 18
IAD12:36 pmWashington, D.C. Dulles Intl
4h 31m
1 stop
STL4:07 pmLambert-St Louis
$197
Find similar
Delta
Oct 3
STL6:42 pmLambert-St Louis
4h 46m
1 stop
BWI12:28 amBaltimore/Washington
Oct 7
BWI7:05 amBaltimore/Washington
4h 21m
1 stop
STL10:26 amLambert-St Louis
$211
Find similar
Delta
Nov 11
STL9:21 amLambert-St Louis
4h 19m
1 stop
IAD2:40 pmWashington, D.C. Dulles Intl
Nov 18
IAD7:01 amWashington, D.C. Dulles Intl
4h 48m
1 stop
STL10:49 amLambert-St Louis
$277
Find similar

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 September 15, 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

Thu 10/2

10:49 am-5:53 pm

1 stop6h 04m

Baltimore/Washington

Mon 10/6

6:22 am-3:04 pm

1 stop9h 42m

$143

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Thu 9/25

10:49 am-5:53 pm

1 stop6h 04m

Baltimore/Washington

Mon 9/29

6:22 am-3:04 pm

1 stop9h 42m

$144

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Tue 10/14

12:51 pm-8:48 pm

1 stop6h 57m

Baltimore/Washington

Wed 10/15

6:13 pm-11:54 pm

1 stop6h 41m

$158

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Thu 11/20

5:00 am-10:58 am

1 stop4h 58m

Baltimore/Washington

Fri 11/28

8:21 pm-12:05 am

1 stop4h 44m

$159

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Mon 11/10

6:09 pm-11:04 pm

1 stop3h 55m

Washington, D.C. Reagan-National

Wed 11/19

8:59 am-1:00 pm

1 stop5h 01m

$197

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Mon 11/10

6:09 pm-11:03 pm

1 stop3h 54m

Washington, D.C. Dulles Intl

Tue 11/18

12:36 pm-4:07 pm

1 stop4h 31m

$197

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Sun 10/5

8:05 am-11:15 am

Nonstop2h 10m

Washington, D.C. Dulles Intl

Sun 10/12

6:30 am-10:49 am

1 stop5h 19m

$212

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Tue 10/21

3:23 pm-9:22 pm

1 stop4h 59m

Baltimore/Washington

Thu 10/23

6:29 am-10:49 am

1 stop5h 20m

$217

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Mon 10/13

8:15 pm-11:15 pm

Nonstop2h 00m

Washington, D.C. Reagan-National

Mon 10/20

3:40 pm-7:30 pm

1 stop4h 50m

$236

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Fri 10/10

3:25 pm-10:25 pm

1 stop6h 00m

Washington, D.C. Reagan-National

Sat 10/11

12:30 pm-9:00 pm

1 stop9h 30m

$247

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

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 November is your next best option. Flight prices from St. Louis to Washington, D.C. during November average around $229.

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 $356. 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 $477.

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 $288. 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 $960. 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 $377 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 $246 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?

No. A direct flight is the cheapest option for a flight between St. Louis to Washington, D.C..

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

As of September 2025, prices for St. Louis to Washington, D.C. flights are approximately 25% 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

$156

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 $156. The best round-trip flight deal from St. Louis to Washington, D.C. found on momondo in the last 72 hours is $253.
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 2h 00m.

  • 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 $124Free CancellationRating
5.8
3,173 reviews
Search Frontier flights
American AirlinesPriceFrom $129Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
DeltaPriceFrom $168Free CancellationRating
7.9
7,956 reviews
Search Delta flights
SouthwestPriceFrom $193Free CancellationRating
8.0
4,245 reviews
Search Southwest flights
United AirlinesPriceFrom $211Free CancellationRating
7.4
8,931 reviews
Search United Airlines flights

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

    Southwest operates around 22 flights from St. Louis to Washington, D.C. every week. The average price of these flights found in the last 72 hours has been $334, but momondo users have found Southwest deals from St. Louis to Washington, D.C. from as low as $193 round-trip. Southwest has been scored 8.0/10 in 4,245 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 $211, round-trip. It should be noted that an average United Airlines flight deal for this route in this time was higher, at $445 round-trip. United Airlines operates 14 flights out of St. Louis into Washington, D.C. in an average week, so prices vary by time and availability. 8,931 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
Gettysburg
National Harbor
Arlington
Woodbridge
Waldorf
Tysons
Laurel
Colonial Beach
Silver Spring
Fredericksburg
Towson
Rockville
Manassas
Reston
Fairfax
Gaithersburg
Glen Burnie
Springfield
Linthicum Heights

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