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Cheap flights from St. Louis to Washington, D.C. from $70

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 1/21. 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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Cheap round-trip flights

Enter your travel dates to find the best prices.
American Airlines Logo
9:54 am - 12:59 pm
STL
-
DCA
2h 05mnonstop
American Airlines Logo
7:40 am - 9:24 am
DCA
-
STL
2h 44mnonstop
$235American Airlines
Wed, Jan 21 - Wed, Jan 28
Southwest Logo
5:10 am - 11:50 am
STL
-
DCA
5h 40m1 stop
Southwest Logo
12:00 pm - 1:35 pm
DCA
-
STL
2h 35mnonstop
$237Southwest
Sat, Jan 17 - Sun, Jan 18
American Airlines Logo
6:00 am - 9:14 am
STL
-
DCA
2h 14mnonstop
American Airlines Logo
1:42 pm - 5:03 pm
DCA
-
STL
4h 21m1 stop
$241American Airlines
Sat, Feb 14 - Tue, Feb 17
American Airlines Logo
3:54 pm - 9:59 pm
STL
-
DCA
5h 05m1 stop
American Airlines Logo
8:10 pm - 9:51 pm
DCA
-
STL
2h 41mnonstop
$243American Airlines
Sat, Jan 17 - Sun, Jan 18
American Airlines Logo
7:00 am - 1:28 pm
STL
-
DCA
5h 28m1 stop
American Airlines Logo
8:10 pm - 9:51 pm
DCA
-
STL
2h 41mnonstop
$245American Airlines
Wed, Feb 4 - Wed, Feb 4
Frontier Logo
7:43 pm - 1:01 pm
STL
-
DCA
16h 18m1 stop
Frontier Logo
2:00 pm - 10:02 am
DCA
-
STL
21h 02m1 stop
$246Frontier
Fri, Jan 9 - Sun, Jan 11
Delta Logo
7:10 am - 3:00 pm
STL
-
DCA
6h 50m1 stop
Delta Logo
6:00 pm - 11:39 pm
DCA
-
STL
6h 39m1 stop
$247Delta
Sat, Jan 17 - Sun, Jan 18
Frontier Logo
1:59 pm - 1:00 pm
STL
-
DCA
22h 01m1 stop
Frontier Logo
8:00 am - 9:13 pm
DCA
-
STL
14h 13m2 stops
$249Frontier
Fri, Feb 27 - Mon, Mar 2
United Airlines Logo
7:00 am - 2:39 pm
STL
-
DCA
6h 39m1 stop
United Airlines Logo
7:00 pm - 10:58 pm
DCA
-
STL
4h 58m1 stop
$250United Airlines
Tue, Feb 10 - Tue, Feb 10
Delta Logo
7:25 am - 12:54 pm
STL
-
DCA
4h 29m1 stop
Delta Logo
10:15 am - 2:47 pm
DCA
-
STL
5h 32m1 stop
$251Delta
Sat, Feb 14 - Tue, Feb 17

American Airlines flights from St. Louis to Washington, D.C. Reagan-National Airport

Our best American Airlines deals on St. Louis to Washington, D.C. Reagan-National Airport flight tickets
American Airlines
Jan 21
STL9:54 amLambert-St Louis
2h 05m
DCA12:59 pmWashington, D.C. Reagan-National
Jan 28
DCA7:40 amWashington, D.C. Reagan-National
2h 44m
STL9:24 amLambert-St Louis
$235
Find similar
American Airlines
Feb 14
STL6:00 amLambert-St Louis
2h 14m
DCA9:14 amWashington, D.C. Reagan-National
Feb 17
DCA1:42 pmWashington, D.C. Reagan-National
4h 21m
1 stop
STL5:03 pmLambert-St Louis
$241
Find similar
American Airlines
Jan 21
STL5:59 pmLambert-St Louis
2h 11m
DCA9:10 pmWashington, D.C. Reagan-National
Jan 28
DCA6:00 amWashington, D.C. Reagan-National
5h 20m
1 stop
STL10:20 amLambert-St Louis
$245
Find similar

Delta flights from St. Louis to Washington, D.C. Reagan-National Airport

Our best Delta deals on St. Louis to Washington, D.C. Reagan-National Airport flight tickets
Delta
Feb 14
STL7:25 amLambert-St Louis
4h 29m
1 stop
DCA12:54 pmWashington, D.C. Reagan-National
Feb 17
DCA10:15 amWashington, D.C. Reagan-National
5h 32m
1 stop
STL2:47 pmLambert-St Louis
$251
Find similar
Delta
Jan 21
STL5:04 pmLambert-St Louis
4h 29m
1 stop
DCA10:33 pmWashington, D.C. Reagan-National
Jan 28
DCA11:00 amWashington, D.C. Reagan-National
6h 39m
1 stop
STL4:39 pmLambert-St Louis
$255
Find similar
Delta
Feb 25
STL10:13 amLambert-St Louis
5h 47m
1 stop
DCA5:00 pmWashington, D.C. Reagan-National
Feb 27
DCA6:00 amWashington, D.C. Reagan-National
7h 23m
1 stop
STL12:23 pmLambert-St Louis
$287
Find similar

momondo Fare Finder

 
Customize your flight search to find flights from St. Louis to Washington, D.C. Reagan-National Airport 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 26, 2025.
Use the filters below to find and compare flights from St. Louis to Washington, D.C. Reagan-National Airport that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 1/21

9:54 am-12:59 pm

Nonstop2h 05m

Washington, D.C. Reagan-National

Wed 1/28

7:40 am-9:24 am

Nonstop2h 44m

$235

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Sat 1/17

5:10 am-11:50 am

1 stop5h 40m

Washington, D.C. Reagan-National

Sun 1/18

12:00 pm-1:35 pm

Nonstop2h 35m

$237

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Sat 2/14

6:00 am-9:14 am

Nonstop2h 14m

Washington, D.C. Reagan-National

Tue 2/17

1:42 pm-5:03 pm

1 stop4h 21m

$241

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Sat 1/17

3:54 pm-9:59 pm

1 stop5h 05m

Washington, D.C. Reagan-National

Sun 1/18

8:10 pm-9:51 pm

Nonstop2h 41m

$243

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 2/4

7:00 am-1:28 pm

1 stop5h 28m

Washington, D.C. Reagan-National

Wed 2/4

8:10 pm-9:51 pm

Nonstop2h 41m

$245

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Fri 1/9

7:43 pm-1:01 pm

1 stop16h 18m

Washington, D.C. Reagan-National

Sun 1/11

2:00 pm-10:02 am

1 stop21h 02m

$246

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Sat 1/17

7:10 am-3:00 pm

1 stop6h 50m

Washington, D.C. Reagan-National

Sun 1/18

6:00 pm-11:39 pm

1 stop6h 39m

$247

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Fri 2/27

1:59 pm-1:00 pm

1 stop22h 01m

Washington, D.C. Reagan-National

Mon 3/2

8:00 am-9:13 pm

2 stops14h 13m

$249

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Tue 2/10

7:00 am-2:39 pm

1 stop6h 39m

Washington, D.C. Reagan-National

Tue 2/10

7:00 pm-10:58 pm

1 stop4h 58m

$250

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Sat 2/14

7:25 am-12:54 pm

1 stop4h 29m

Washington, D.C. Reagan-National

Tue 2/17

10:15 am-2:47 pm

1 stop5h 32m

$251

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. Reagan-National Airport

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. Reagan-National Airport?

The month of August is, on average, the cheapest month to fly to Washington, D.C. Reagan-National Airport from St. Louis, with most prices found around $253. If you aren’t able to travel to Washington, D.C. Reagan-National Airport during the month of August, then flying in April is also cheap. Prices for this month can be found on momondo for an average of $273.

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

The cheapest day to depart from St. Louis to Washington, D.C. Reagan-National Airport is on a Saturday. Travelers who choose to depart for Washington, D.C. Reagan-National Airport on a Saturday will often find tickets for as low as $287. Flights from St. Louis to Washington, D.C. Reagan-National Airport on a Sunday will generally be more expensive and average around $389. Keep in mind that these prices on both days could fluctuate depending on the season and the demand.

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

Our data shows that the cheapest St. Louis to Washington, D.C. Reagan-National Airport flights are usually those with departure times in the evening. Our users have found flights to Washington, D.C. Reagan-National Airport in the evening for as low as $300. In contrast, the most expensive time of day to depart to Washington, D.C. Reagan-National Airport is in the morning when prices are around $347.

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

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

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

You are more likely to see cheaper flights to Washington, D.C. Reagan-National Airport from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Washington, D.C. Reagan-National Airport for around $296 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Washington, D.C. Reagan-National Airport from St. Louis for as low as $216 on momondo.

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

There are 3 cabin classes available to choose from on Lambert-St Louis to Washington, D.C. Reagan-National 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. Reagan-National Airport flights?

You could potentially save up to 2% on your flight if you consider stops on a St. Louis to Washington, D.C. Reagan-National Airport flight.

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

As of December 2025, prices for St. Louis to Washington, D.C. Reagan-National Airport flights are approximately 36% more expensive when compared to flights at the same time last year.

When to book flights from St. Louis to Washington, D.C. Reagan-National Airport

Are you open to changing your travel dates? Check out the ideal times to fly from St. Louis to Washington, D.C. Reagan-National Airport 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. Reagan-National Airport (STL to DCA) flight deals and tips

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

Best Price Found

$188

Fastest flight time

1h 55m

Direct flights

Every day
The best one-way flight to Washington, D.C. Reagan-National Airport from St. Louis in the past 72 hours is $188. The best round-trip flight deal from St. Louis to Washington, D.C. Reagan-National Airport found on momondo in the last 72 hours is $296.
The fastest flight from St. Louis to Washington, D.C. Reagan-National Airport takes 1h 55m
Direct flights go from St. Louis to Washington, D.C. Reagan-National Airport every day.
Search flight deals

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

    Washington, D.C. Reagan-National is 708.3 mi away from Lambert-St Louis. In terms of flight time, this usually takes a little over 1h 55m.

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

    Prices for flights from Lambert-St Louis Airport to Washington, D.C. Reagan-National Airport were last updated today.

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

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

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

    The necessary travel and health documents for your Washington, D.C. Reagan-National Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

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

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

Best airlines flying from St. Louis to Washington, D.C. Reagan-National Airport

Compare and see reviews for airlines that fly from St. Louis to Washington, D.C. Reagan-National Airport with momondo
Airline
Rating
Free Cancellation
Price
FrontierPriceFrom $124Free CancellationRating
5.8
3,070 reviews
Search Frontier flights
American AirlinesPriceFrom $177Free CancellationRating
7.2
11,066 reviews
Search American Airlines flights
SouthwestPriceFrom $197Free CancellationRating
8.0
4,258 reviews
Search Southwest flights

  • Southwest Flights From St. Louis to Washington, D.C. Reagan-National Airport

    The lowest priced Southwest flight from St. Louis to Washington, D.C. Reagan-National Airport from the last 72 hours was $197. Generally, Southwest has 24 flights on this route every week with an average price of $309. Southwest is rated 8.0/10 by our users.

  • American Airlines Flights From St. Louis to Washington, D.C. Reagan-National Airport

    The best American Airlines deal for St. Louis to Washington, D.C. Reagan-National Airport flight tickets found on momondo in the last 72 hours was $177, round-trip. It should be noted that an average American Airlines flight deal for this route in this time was higher, at $295 round-trip. American Airlines operates 12 flights out of St. Louis into Washington, D.C. Reagan-National Airport in an average week, so prices vary by time and availability. 11,066 American Airlines reviews by users on momondo have scored the airline at 7.2/10.

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
Waldorf
Woodbridge
Tysons
Laurel
Colonial Beach
Silver Spring
Fredericksburg
Towson
Rockville
Gaithersburg
Reston
Manassas
Fairfax
Glen Burnie
Linthicum Heights
Bethesda

Why use momondo?

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

momondo compares prices from hundreds of airlines and agents so you can find and book the best deal on flights from St. Louis to Washington, D.C.. Millions of users trust and use momondo every year so you are in good hands.

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

Yes. momondo enables you to select and highlight flights to Washington, D.C. from St. Louis with this policy.

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

Once you have performed a search in the form on the page, momondo provides useful filters and insights. We can show you the cheapest days and times to fly as well as help filter your options to help you make an informed choice when booking flights to Washington, D.C. from St. Louis.

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

Price alerts on flights to Washington, D.C. from St. Louis are quick and easy to set up on momondo. Simply perform a search and select the price alert feature. It is as simple as that.

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