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Cheap flights from St. Louis to Washington, D.C. from $97

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 9/7. 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. (STL-DCA)

Cheap round-trip flights

Frontier Logo
7:55 pm - 12:10 pmSTL-DCA
15h 15m1 stop
Frontier Logo
7:00 am - 9:06 amDCA-STL
27h 06m1 stop
$196Frontier
Find Deal
Sun, Sep 7 - Wed, Sep 17
Frontier Logo
7:54 pm - 4:59 pmSTL-DCA
20h 05m1 stop
Frontier Logo
7:00 am - 9:06 amDCA-STL
27h 06m1 stop
$216Frontier
Find Deal
Sat, Aug 30 - Wed, Sep 3
Frontier Logo
7:55 pm - 12:10 pmSTL-DCA
15h 15m1 stop
Frontier Logo
6:00 pm - 9:06 amDCA-STL
16h 06m1 stop
$225Frontier
Find Deal
Wed, Sep 17 - Tue, Sep 23
Frontier Logo
7:55 pm - 12:10 pmSTL-DCA
15h 15m1 stop
Frontier Logo
6:00 pm - 9:06 amDCA-STL
16h 06m1 stop
$226Frontier
Find Deal
Sun, Sep 7 - Fri, Sep 12
Southwest Logo
7:20 pm - 10:25 pmSTL-DCA
2h 05mnonstop
Southwest Logo
8:00 am - 9:10 amDCA-STL
2h 10mnonstop
$245Southwest
Find Deal
Wed, Sep 24 - Mon, Sep 29
Southwest Logo
3:05 pm - 6:05 pmSTL-DCA
2h 00mnonstop
Southwest Logo
11:00 am - 5:05 pmDCA-STL
7h 05m2 stops
$252Southwest
Find Deal
Tue, Jan 13 - Tue, Jan 27
Southwest Logo
8:00 am - 11:00 amSTL-DCA
2h 00mnonstop
Southwest Logo
8:00 am - 9:10 amDCA-STL
2h 10mnonstop
$253Southwest
Find Deal
Thu, Sep 11 - Mon, Sep 15
American Airlines Logo
7:01 am - 10:03 amSTL-DCA
2h 02mnonstop
American Airlines Logo
5:59 pm - 7:23 pmDCA-STL
2h 24mnonstop
$254American Airlines
Find Deal
Sat, Oct 4 - Sat, Oct 11
American Airlines Logo
9:56 am - 4:29 pmSTL-DCA
5h 33m1 stop
American Airlines Logo
5:59 pm - 7:23 pmDCA-STL
2h 24mnonstop
$264American Airlines
Find Deal
Sat, Oct 4 - Sat, Oct 11
American Airlines Logo
6:08 pm - 9:10 pmSTL-DCA
2h 02mnonstop
American Airlines Logo
4:31 pm - 5:48 pmDCA-STL
2h 17mnonstop
$285American Airlines
Find Deal
Thu, Oct 9 - Sun, Oct 12

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

Our best Southwest deals on St. Louis to Washington, D.C. Reagan-National Airport flight tickets
Southwest
Sep 24
STL7:20 pmLambert-St Louis
2h 05m
DCA10:25 pmWashington, D.C. Reagan-National
Sep 29
DCA8:00 amWashington, D.C. Reagan-National
2h 10m
STL9:10 amLambert-St Louis
$245
Find similar
Southwest
Jan 13
STL3:05 pmLambert-St Louis
2h 00m
DCA6:05 pmWashington, D.C. Reagan-National
Jan 27
DCA11:00 amWashington, D.C. Reagan-National
7h 05m
2 stops
STL5:05 pmLambert-St Louis
$252
Find similar
Southwest
Sep 11
STL8:00 amLambert-St Louis
2h 00m
DCA11:00 amWashington, D.C. Reagan-National
Sep 15
DCA8:00 amWashington, D.C. Reagan-National
2h 10m
STL9:10 amLambert-St Louis
$253
Find similar

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

Our best Frontier deals on St. Louis to Washington, D.C. Reagan-National Airport flight tickets
Frontier
Sep 7
STL7:55 pmLambert-St Louis
15h 15m
1 stop
DCA12:10 pmWashington, D.C. Reagan-National
Sep 17
DCA7:00 amWashington, D.C. Reagan-National
27h 06m
1 stop
STL9:06 amLambert-St Louis
$196
Find similar
Frontier
Aug 30
STL7:54 pmLambert-St Louis
20h 05m
1 stop
DCA4:59 pmWashington, D.C. Reagan-National
Sep 3
DCA7:00 amWashington, D.C. Reagan-National
27h 06m
1 stop
STL9:06 amLambert-St Louis
$216
Find similar
Frontier
Sep 17
STL7:55 pmLambert-St Louis
15h 15m
1 stop
DCA12:10 pmWashington, D.C. Reagan-National
Sep 23
DCA6:00 pmWashington, D.C. Reagan-National
16h 06m
1 stop
STL9:06 amLambert-St Louis
$225
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 August 20, 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

Sun 9/7

7:55 pm-12:10 pm

1 stop15h 15m

Washington, D.C. Reagan-National

Wed 9/17

7:00 am-9:06 am

1 stop27h 06m

$196

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Sat 8/30

7:54 pm-4:59 pm

1 stop20h 05m

Washington, D.C. Reagan-National

Wed 9/3

7:00 am-9:06 am

1 stop27h 06m

$216

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 9/17

7:55 pm-12:10 pm

1 stop15h 15m

Washington, D.C. Reagan-National

Tue 9/23

6:00 pm-9:06 am

1 stop16h 06m

$225

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Sun 9/7

7:55 pm-12:10 pm

1 stop15h 15m

Washington, D.C. Reagan-National

Fri 9/12

6:00 pm-9:06 am

1 stop16h 06m

$226

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 9/24

7:20 pm-10:25 pm

Nonstop2h 05m

Washington, D.C. Reagan-National

Mon 9/29

8:00 am-9:10 am

Nonstop2h 10m

$245

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Tue 1/13

3:05 pm-6:05 pm

Nonstop2h 00m

Washington, D.C. Reagan-National

Tue 1/27

11:00 am-5:05 pm

2 stops7h 05m

$252

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Thu 9/11

8:00 am-11:00 am

Nonstop2h 00m

Washington, D.C. Reagan-National

Mon 9/15

8:00 am-9:10 am

Nonstop2h 10m

$253

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Sat 10/4

7:01 am-10:03 am

Nonstop2h 02m

Washington, D.C. Reagan-National

Sat 10/11

5:59 pm-7:23 pm

Nonstop2h 24m

$254

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Sat 10/4

9:56 am-4:29 pm

1 stop5h 33m

Washington, D.C. Reagan-National

Sat 10/11

5:59 pm-7:23 pm

Nonstop2h 24m

$264

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Thu 10/9

6:08 pm-9:10 pm

Nonstop2h 02m

Washington, D.C. Reagan-National

Sun 10/12

4:31 pm-5:48 pm

Nonstop2h 17m

$285

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 September is also cheap. Prices for this month can be found on momondo for an average of $258.

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 $293. Flights from St. Louis to Washington, D.C. Reagan-National Airport on a Sunday will generally be more expensive and average around $382. 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 $285. 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 $335.

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 $289 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 2 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.

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

As of August 2025, prices for St. Louis to Washington, D.C. Reagan-National Airport flights are approximately 23% cheaper 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

$137

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 $137. 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 $222.
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 2h 00m.

  • 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
American AirlinesPriceFrom $154Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
SouthwestPriceFrom $192Free CancellationRating
8.0
4,246 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 $192. Generally, Southwest has 23 flights on this route every week with an average price of $293. 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 $154, round-trip. It should be noted that an average American Airlines flight deal for this route in this time was higher, at $288 round-trip. American Airlines operates 18 flights out of St. Louis into Washington, D.C. Reagan-National Airport in an average week, so prices vary by time and availability. 10,000 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
Gettysburg
Arlington
National Harbor
Woodbridge
Waldorf
Tysons
Silver Spring
Laurel
Colonial Beach
Fredericksburg
Manassas
Towson
Rockville
Gaithersburg
Reston
Fairfax
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 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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