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Cheap flights from Washington, D.C. Reagan-National Airport to St. Louis from $123

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Washington, D.C. Reagan-National Airport to St. Louis departing on 9/26. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
1 adult
1 adult, Economy, 0 bags

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from Washington, D.C. Reagan-National Airport to St. Louis

Cheap round-trip flights

Enter your travel dates to find the best prices.
Frontier Logo
7:00 am - 7:15 pm
DCA
-
STL
13h 15m
1 stop
Frontier Logo
8:10 pm - 9:58 pm
STL
-
DCA
24h 48m
1 stop
$246Frontier
Thu, Oct 8 - Sun, Oct 11
American Airlines Logo
7:16 pm - 10:42 pm
DCA
-
STL
4h 26m
1 stop
American Airlines Logo
6:00 am - 9:19 am
STL
-
DCA
2h 19mnonstop
$247American Airlines
Sat, Sep 19 - Mon, Sep 21
Southwest Logo
6:35 pm - 10:00 pm
DCA
-
STL
4h 25m
1 stop
Southwest Logo
7:50 pm - 10:50 pm
STL
-
DCA
2h 00mnonstop
$247Southwest
Wed, Oct 7 - Thu, Oct 8
Southwest Logo
8:00 am - 9:25 am
DCA
-
STL
2h 25mnonstop
Southwest Logo
3:05 pm - 9:50 pm
STL
-
DCA
5h 45m
1 stop
$247Southwest
Mon, Oct 12 - Thu, Oct 15
Southwest Logo
12:15 pm - 1:40 pm
DCA
-
STL
2h 25mnonstop
Southwest Logo
5:00 am - 11:15 am
STL
-
DCA
5h 15m
1 stop
$247Southwest
Tue, Nov 3 - Thu, Nov 5
American Airlines Logo
8:05 am - 12:55 pm
DCA
-
STL
5h 50m
1 stop
American Airlines Logo
6:00 am - 9:14 am
STL
-
DCA
2h 14mnonstop
$247American Airlines
Sat, Sep 5 - Mon, Sep 7
American Airlines Logo
3:47 pm - 9:08 pm
DCA
-
STL
6h 21m
1 stop
American Airlines Logo
6:00 am - 9:18 am
STL
-
DCA
2h 18mnonstop
$247American Airlines
Sat, Dec 12 - Sat, Jan 9
Frontier Logo
7:00 am - 7:13 pm
DCA
-
STL
13h 13m
1 stop
Frontier Logo
7:58 pm - 4:59 pm
STL
-
DCA
20h 01m
1 stop
$248Frontier
Thu, Aug 20 - Mon, Aug 24
Frontier Logo
1:06 pm - 7:17 pm
DCA
-
STL
7h 11m
1 stop
Frontier Logo
8:10 pm - 9:59 pm
STL
-
DCA
24h 49m
1 stop
$250Frontier
Mon, Sep 21 - Wed, Sep 23
Frontier Logo
7:00 am - 7:13 pm
DCA
-
STL
13h 13m
1 stop
Frontier Logo
7:58 pm - 4:59 pm
STL
-
DCA
20h 01m
1 stop
$250Frontier
Mon, Aug 24 - Thu, Aug 27

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

Our best Southwest deals on Washington, D.C. Reagan-National Airport to St. Louis flight tickets
Southwest
Sep 3
DCA8:15 amWashington, D.C. Reagan-National
2h 20m
STL9:35 amLambert-St Louis
Sep 6
STL7:35 amLambert-St Louis
4h 05m
1 stop
DCA12:40 pmWashington, D.C. Reagan-National
$252
Southwest
Aug 20
DCA4:35 pmWashington, D.C. Reagan-National
6h 30m
1 stop
STL10:05 pmLambert-St Louis
Aug 24
STL10:10 amLambert-St Louis
6h 50m
2 stops
DCA6:00 pmWashington, D.C. Reagan-National
$262
Southwest
Sep 3
DCA6:05 amWashington, D.C. Reagan-National
6h 55m
1 stop
STL12:00 pmLambert-St Louis
Sep 7
STL2:45 pmLambert-St Louis
6h 40m
1 stop
DCA10:25 pmWashington, D.C. Reagan-National
$276

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

Our best American Airlines deals on Washington, D.C. Reagan-National Airport to St. Louis flight tickets
American Airlines
Oct 10
DCA8:35 pmWashington, D.C. Reagan-National
4h 23m
1 stop
STL11:58 pmLambert-St Louis
Oct 12
STL5:08 pmLambert-St Louis
2h 10m
DCA8:18 pmWashington, D.C. Reagan-National
$247
American Airlines
Dec 28
DCA8:14 pmWashington, D.C. Reagan-National
2h 31m
STL9:45 pmLambert-St Louis
Jan 6
STL6:00 amLambert-St Louis
2h 18m
DCA9:18 amWashington, D.C. Reagan-National
$281
American Airlines
Aug 28
DCA7:59 pmWashington, D.C. Reagan-National
2h 29m
STL9:28 pmLambert-St Louis
Aug 31
STL6:00 amLambert-St Louis
2h 14m
DCA9:14 amWashington, D.C. Reagan-National
$286

momondo Fare Finder

 
Customize your flight search to find flights from Washington, D.C. Reagan-National Airport to St. Louis 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 July 30, 2026.
Use the filters below to find and compare flights from Washington, D.C. Reagan-National Airport to St. Louis that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Thu 10/8

7:00 am-7:15 pm

1 stop13h 15m

Lambert-St Louis

Sun 10/11

8:10 pm-9:58 pm

1 stop24h 48m

$246

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Sat 9/19

7:16 pm-10:42 pm

1 stop4h 26m

Lambert-St Louis

Mon 9/21

6:00 am-9:19 am

Nonstop2h 19m

$247
Quickest round-trip

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Wed 10/7

6:35 pm-10:00 pm

1 stop4h 25m

Lambert-St Louis

Thu 10/8

7:50 pm-10:50 pm

Nonstop2h 00m

$247

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Mon 10/12

8:00 am-9:25 am

Nonstop2h 25m

Lambert-St Louis

Thu 10/15

3:05 pm-9:50 pm

1 stop5h 45m

$247

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Tue 11/3

12:15 pm-1:40 pm

Nonstop2h 25m

Lambert-St Louis

Thu 11/5

5:00 am-11:15 am

1 stop5h 15m

$247

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Sat 9/5

8:05 am-12:55 pm

1 stop5h 50m

Lambert-St Louis

Mon 9/7

6:00 am-9:14 am

Nonstop2h 14m

$247

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Sat 12/12

3:47 pm-9:08 pm

1 stop6h 21m

Lambert-St Louis

Sat 1/9

6:00 am-9:18 am

Nonstop2h 18m

$247

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Thu 8/20

7:00 am-7:13 pm

1 stop13h 13m

Lambert-St Louis

Mon 8/24

7:58 pm-4:59 pm

1 stop20h 01m

$248

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Mon 9/21

1:06 pm-7:17 pm

1 stop7h 11m

Lambert-St Louis

Wed 9/23

8:10 pm-9:59 pm

1 stop24h 49m

$250

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Mon 8/24

7:00 am-7:13 pm

1 stop13h 13m

Lambert-St Louis

Thu 8/27

7:58 pm-4:59 pm

1 stop20h 01m

$250

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
1
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See travel insights to St. Louis from

How to get the cheapest flight ticket from Washington, D.C. Reagan-National Airport to St. Louis

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 Washington, D.C. Reagan-National Airport and St. Louis?

Prices are currently low for flights on this route.

Typical prices usually range from $256 to $513.
The lowest price recently found on this route was $246.

What is the cheapest month to fly to St. Louis?

In general, August is the cheapest month to fly from Washington, D.C. Reagan-National Airport to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $301. The month of October is another great option to travel to St. Louis, with average flight prices from Washington, D.C. Reagan-National Airport averaging around $309.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Wednesday when prices can be found for as low as $345. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Monday because tickets tend to average around $460. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Washington, D.C. Reagan-National Airport at noon is the least expensive time of day to depart. momondo users have found prices as low as $371 when looking at flights departing at noon. In the afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $413 per ticket.

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

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

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

You are more likely to see cheaper flights to St. Louis from Washington, D.C. Reagan-National Airport when booking weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $377 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Washington, D.C. Reagan-National Airport for as low as $254 on momondo.

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

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

You could potentially save up to 4% on your flight if you consider stops on a Washington, D.C. Reagan-National Airport to St. Louis flight.

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

As of July 2026, prices for Washington, D.C. Reagan-National Airport to St. Louis flights are approximately 40% more expensive when compared to flights at the same time last year.

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

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

Cheap Washington, D.C. Reagan-National Airport to St. Louis (DCA to STL) flight deals and tips

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

Best Price Found

$169

Fastest flight time

2h 10m

Direct flights

Every day

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Washington, D.C. Reagan-National Airport in the past 72 hours is $169. The best round-trip flight deal from Washington, D.C. Reagan-National Airport to St. Louis found on momondo in the last 72 hours is $313.
The fastest flight from Washington, D.C. Reagan-National Airport to St. Louis takes 2h 10m
Direct flights go from Washington, D.C. Reagan-National Airport to St. Louis every day.
There is 1 airport in St. Louis. From Washington, D.C. Reagan-National Airport there are direct flights to Lambert-St Louis (STL).
Search flight deals

Frequently asked questions about flying from Washington, D.C. Reagan-National Airport to St. Louis

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

    Washington, D.C. Reagan-National and Lambert-St Louis are 708.3 mi apart from one another. In terms of flight time, this usually takes a little over 2h 10m.

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

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

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

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

    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 Washington, D.C. Reagan-National Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The travel and health documents required for your trip to Lambert-St Louis Airport 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 Lambert-St Louis Airport. 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 Washington, D.C. Reagan-National Airport to St. Louis?

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

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

Compare and see reviews for airlines that fly from Washington, D.C. Reagan-National Airport to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
American AirlinesPriceFrom $204Free CancellationRating
7.1
11,841 reviews
Search American Airlines flights
SouthwestPriceFrom $216Free CancellationRating
8.0
4,227 reviews
Search Southwest flights

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

    Southwest flies from Washington, D.C. Reagan-National Airport to St. Louis around 13 times per week, with 4,227 momondo users rating the airline 8.0/10. The cheapest Southwest deal from Washington, D.C. Reagan-National Airport to St. Louis in the last 72 hours was $216 (round-trip), much lower than the average airfare cost of $388 for Southwest flights on this route.

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

    American Airlines (7.1/10 from 11,842 reviews) operates around 13 flights from Washington, D.C. Reagan-National Airport to St. Louis in any given week. The average American Airlines airfare for this route is around $374, with deals from around $204 rare but found on momondo. Referenced prices are for round-trip Washington, D.C. Reagan-National Airport to St. Louis flight searches in the last 72 hours.

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Fairview Heights
Hermann
St. Peters
Maryland Heights
Florissant
Collinsville
O'Fallon
Alton
Fenton
Farmington
Clayton
Wentzville
Festus
Eureka
Litchfield
Edwardsville
Grafton
Shrewsbury

Why use momondo?

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

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

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

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

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

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from Washington, D.C. to St. Louis.

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

Price alerts on flights to St. Louis from Washington, D.C. 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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