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Cheap flights from St. Louis to Washington, D.C. from $40

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 11/17. 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.
Frontier Logo
4:56 pm - 12:13 amSTL-BWI
6h 17m1 stop
Frontier Logo
5:50 am - 10:12 amBWI-STL
5h 22m1 stop
$165Frontier
Find Deal
Fri, Nov 7 - Sun, Nov 9
Frontier Logo
4:56 pm - 12:13 amSTL-BWI
6h 17m1 stop
Frontier Logo
10:16 am - 3:38 pmBWI-STL
6h 22m1 stop
$182Frontier
Find Deal
Fri, Nov 7 - Sat, Nov 8
American Airlines Logo
6:00 am - 9:10 amSTL-DCA
2h 10mnonstop
American Airlines Logo
2:55 pm - 4:36 pmDCA-STL
2h 41mnonstop
$214American Airlines
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Fri, Oct 31 - Mon, Nov 3
Delta Logo
6:40 am - 11:47 amSTL-DCA
4h 07m1 stop
Delta Logo
6:00 am - 9:37 amDCA-STL
4h 37m1 stop
$219Delta
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Wed, Nov 5 - Thu, Nov 6
Delta Logo
6:14 pm - 11:02 pmSTL-BWI
3h 48m1 stop
Delta Logo
6:00 am - 9:46 amBWI-STL
4h 46m1 stop
$219Delta
Find Deal
Tue, Nov 4 - Sun, Nov 9
Southwest Logo
3:25 pm - 6:30 pmSTL-DCA
2h 05mnonstop
Southwest Logo
6:55 pm - 10:10 pmDCA-STL
4h 15m1 stop
$224Southwest
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Fri, Oct 31 - Mon, Nov 3
Southwest Logo
12:45 pm - 7:55 pmSTL-BWI
6h 10m2 stops
Southwest Logo
3:00 pm - 7:25 pmBWI-STL
5h 25m1 stop
$224Southwest
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Tue, Nov 18 - Tue, Dec 2
United Airlines Logo
8:25 am - 11:33 amSTL-IAD
2h 08mnonstop
United Airlines Logo
6:00 am - 10:49 amIAD-STL
5h 49m1 stop
$230United Airlines
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Fri, Nov 14 - Sun, Nov 16
American Airlines Logo
6:14 pm - 9:26 pmSTL-DCA
2h 12mnonstop
American Airlines Logo
11:40 am - 1:09 pmDCA-STL
2h 29mnonstop
$231American Airlines
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Fri, Nov 7 - Sat, Nov 8
United Airlines Logo
1:10 pm - 4:17 pmSTL-IAD
2h 07mnonstop
United Airlines Logo
8:40 am - 10:07 amIAD-STL
2h 27mnonstop
$234United Airlines
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Sun, Nov 2 - Sat, Nov 8

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

Our best Delta deals on St. Louis to Washington, D.C. flight tickets
Delta
Nov 4
STL6:14 pmLambert-St Louis
3h 46m
1 stop
IAD11:00 pmWashington, D.C. Dulles Intl
Nov 8
IAD3:33 pmWashington, D.C. Dulles Intl
4h 10m
1 stop
STL6:43 pmLambert-St Louis
$219
Find similar
Delta
Feb 20
STL7:05 pmLambert-St Louis
4h 02m
1 stop
IAD12:07 amWashington, D.C. Dulles Intl
Feb 28
IAD6:00 amWashington, D.C. Dulles Intl
6h 50m
1 stop
STL11:50 amLambert-St Louis
$266
Find similar
Delta
Oct 31
STL9:31 amLambert-St Louis
5h 41m
1 stop
DCA4:12 pmWashington, D.C. Reagan-National
Nov 10
DCA7:35 pmWashington, D.C. Reagan-National
5h 09m
1 stop
STL11:44 pmLambert-St Louis
$278
Find similar

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

Our best Frontier deals on St. Louis to Washington, D.C. flight tickets
Frontier
Nov 7
STL4:56 pmLambert-St Louis
6h 17m
1 stop
BWI12:13 amBaltimore/Washington
Nov 9
BWI5:50 amBaltimore/Washington
5h 22m
1 stop
STL10:12 amLambert-St Louis
$165
Find similar
Frontier
Nov 7
STL4:56 pmLambert-St Louis
6h 17m
1 stop
BWI12:13 amBaltimore/Washington
Nov 8
BWI10:16 amBaltimore/Washington
6h 22m
1 stop
STL3:38 pmLambert-St Louis
$182
Find similar
Frontier
Nov 14
STL4:56 pmLambert-St Louis
6h 17m
1 stop
BWI12:13 amBaltimore/Washington
Nov 16
BWI10:21 amBaltimore/Washington
24h 19m
1 stop
STL9:40 amLambert-St Louis
$184
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 October 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

Fri 11/7

4:56 pm-12:13 am

1 stop6h 17m

Baltimore/Washington

Sun 11/9

5:50 am-10:12 am

1 stop5h 22m

$165

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Fri 11/7

4:56 pm-12:13 am

1 stop6h 17m

Baltimore/Washington

Sat 11/8

10:16 am-3:38 pm

1 stop6h 22m

$182

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Fri 10/31

6:00 am-9:10 am

Nonstop2h 10m

Washington, D.C. Reagan-National

Mon 11/3

2:55 pm-4:36 pm

Nonstop2h 41m

$214

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 11/5

6:40 am-11:47 am

1 stop4h 07m

Washington, D.C. Reagan-National

Thu 11/6

6:00 am-9:37 am

1 stop4h 37m

$219

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Tue 11/4

6:14 pm-11:02 pm

1 stop3h 48m

Baltimore/Washington

Sun 11/9

6:00 am-9:46 am

1 stop4h 46m

$219

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Fri 10/31

3:25 pm-6:30 pm

Nonstop2h 05m

Washington, D.C. Reagan-National

Mon 11/3

6:55 pm-10:10 pm

1 stop4h 15m

$224

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Tue 11/18

12:45 pm-7:55 pm

2 stops6h 10m

Baltimore/Washington

Tue 12/2

3:00 pm-7:25 pm

1 stop5h 25m

$224

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Fri 11/14

8:25 am-11:33 am

Nonstop2h 08m

Washington, D.C. Dulles Intl

Sun 11/16

6:00 am-10:49 am

1 stop5h 49m

$230

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Fri 11/7

6:14 pm-9:26 pm

Nonstop2h 12m

Washington, D.C. Reagan-National

Sat 11/8

11:40 am-1:09 pm

Nonstop2h 29m

$231

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Sun 11/2

1:10 pm-4:17 pm

Nonstop2h 07m

Washington, D.C. Dulles Intl

Sat 11/8

8:40 am-10:07 am

Nonstop2h 27m

$234

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 November is your next best option. Flight prices from St. Louis to Washington, D.C. during November average around $230.

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 $347. 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 $479.

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 $296. 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 $932. 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 Baltimore/Washington 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 $373 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?

You could potentially save up to 5% 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 October 2025, prices for St. Louis to Washington, D.C. flights are approximately 153% 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

$168

Fastest flight time

1h 55m

Direct flights

Every day

Airports in Washington, D.C.

3 airports
The best one-way flight to Washington, D.C. from St. Louis in the past 72 hours is $168. The best round-trip flight deal from St. Louis to Washington, D.C. found on momondo in the last 72 hours is $300.
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 3 airports near Washington, D.C.: Washington, D.C. Reagan-National (DCA), Baltimore/Washington (BWI), Washington, D.C. Dulles Intl (IAD)
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  • 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
3,135 reviews
Search Frontier flights
DeltaPriceFrom $124Free CancellationRating
7.9
7,975 reviews
Search Delta flights
American AirlinesPriceFrom $172Free CancellationRating
7.2
11,042 reviews
Search American Airlines flights
SouthwestPriceFrom $198Free CancellationRating
8.0
4,238 reviews
Search Southwest flights
United AirlinesPriceFrom $229Free CancellationRating
7.4
8,976 reviews
Search United Airlines flights

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

    Southwest operates around 20 flights from St. Louis to Washington, D.C. every week. The average price of these flights found in the last 72 hours has been $337, but momondo users have found Southwest deals from St. Louis to Washington, D.C. from as low as $198 round-trip. Southwest has been scored 8.0/10 in 4,238 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 $229, round-trip. It should be noted that an average United Airlines flight deal for this route in this time was higher, at $432 round-trip. United Airlines operates 10 flights out of St. Louis into Washington, D.C. in an average week, so prices vary by time and availability. 8,976 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
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

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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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