What airlines fly to Washington, D.C.?

Southwest, American Airlines and United Airlines are the top three most popular airlines that fly to Washington, D.C. from St. Louis according to our data. Southwest is the first choice among our users, with 55% of people opting to fly with this airline when traveling to Washington, D.C.. Keep in mind that there are 5 different airlines that fly to Washington, D.C. on a routine basis, so you have a few additional options to choose from.

How many flights depart from St. Louis to Washington, D.C. on average per day?

The number of flights available between St. Louis and Washington, D.C. is 8 per day as of August 2026. The most frequent departure time is 8:00AM, with 52% of daily flights leaving at noon.

What is the cheapest airline that flies from Lambert-St Louis to Washington, D.C.?

Frontier, Southwest, and Delta are the most popular carriers operating from Lambert-St Louis to Washington, D.C.

How many flights depart from St. Louis to Washington, D.C. on average per week?

The number of flights available between St. Louis and Washington, D.C. is 60 per week as of August 2026. The most frequent departure day is Mon, with 33% of weekly flights leaving on this day.

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.?

The number of operators available for flights from Lambert-St Louis Airport to Washington, D.C. is 5 as of August 2026.

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.

$67 Cheap Flights from St. Louis to Washington, D.C. in 2026

Discover deals from 900+ travel sites with momondo.

Find the cheapest flights from St. Louis to Washington, D.C.

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

2:29 pm - 11:04 pm

STL

BWI

7h 35m

1 stop

6:00 am - 1:10 pm

BWI

STL

8h 10m

1 stop

$139Frontier

Mon, Sep 14 - Mon, Sep 21

2:29 pm - 11:04 pm

STL

BWI

7h 35m

1 stop

6:00 am - 1:10 pm

BWI

STL

8h 10m

1 stop

$140Frontier

Mon, Sep 14 - Mon, Sep 21

10:44 am - 2:17 pm

STL

DCA

2h 33mnonstop

5:23 pm - 12:14 am

DCA

STL

7h 51m

1 stop

$260American Airlines

Thu, Sep 3 - Mon, Sep 7

1:15 pm - 9:55 pm

STL

DCA

7h 40m

2 stops

6:00 am - 9:25 am

DCA

STL

4h 25m

1 stop

$262Southwest

Sat, Sep 5 - Sun, Sep 6

8:30 am - 3:40 pm

STL

DCA

6h 10m

1 stop

6:30 am - 1:15 pm

DCA

STL

7h 45m

2 stops

$262Southwest

Thu, Sep 17 - Sat, Sep 19

5:30 pm - 11:26 pm

STL

IAD

4h 56m

1 stop

6:00 am - 9:20 am

IAD

STL

4h 20m

1 stop

$262Delta

Wed, Sep 2 - Sun, Sep 6

6:00 am - 2:05 pm

STL

IAD

7h 05m

1 stop

11:10 am - 4:38 pm

IAD

STL

6h 28m

1 stop

$262Delta

Tue, Sep 1 - Sun, Sep 6

6:54 pm - 12:44 am

STL

IAD

4h 50m

1 stop

8:25 am - 9:39 am

IAD

STL

2h 14mnonstop

$266United Airlines

Sat, Sep 5 - Mon, Sep 7

8:30 am - 11:40 am

STL

IAD

2h 10mnonstop

1:05 pm - 6:06 pm

IAD

STL

6h 01m

1 stop

$266United Airlines

Thu, Nov 26 - Wed, Dec 2

7:00 am - 10:08 am

STL

DCA

2h 08mnonstop

8:25 am - 10:09 am

DCA

STL

2h 44mnonstop

$267American Airlines

Thu, Nov 5 - Mon, Nov 9

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

Our best Delta deals on St. Louis to Washington, D.C. flight tickets

Delta

Sep 1

STL6:00 amLambert-St Louis

7h 05m

1 stop

IAD2:05 pmWashington, D.C. Dulles Intl

Sep 6

IAD11:10 amWashington, D.C. Dulles Intl

6h 28m

1 stop

STL4:38 pmLambert-St Louis

$262

Delta

Sep 3

STL7:00 amLambert-St Louis

16h 34m

1 stop

IAD12:34 amWashington, D.C. Dulles Intl

Sep 8

IAD8:08 amWashington, D.C. Dulles Intl

7h 00m

1 stop

STL2:08 pmLambert-St Louis

$276

Delta

Sep 4

STL6:25 pmLambert-St Louis

4h 01m

1 stop

IAD11:26 pmWashington, D.C. Dulles Intl

Sep 10

IAD8:08 amWashington, D.C. Dulles Intl

7h 00m

1 stop

STL2:08 pmLambert-St Louis

$316

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

Aug 29

STL8:00 amLambert-St Louis

4h 55m

1 stop

IAD1:55 pmWashington, D.C. Dulles Intl

Sep 6

IAD8:25 amWashington, D.C. Dulles Intl

2h 14m

STL9:39 amLambert-St Louis

$266

United Airlines

Aug 25

STL8:40 amLambert-St Louis

2h 14m

IAD11:54 amWashington, D.C. Dulles Intl

Aug 27

IAD8:25 amWashington, D.C. Dulles Intl

2h 14m

STL9:39 amLambert-St Louis

$275

United Airlines

Sep 5

STL3:32 pmLambert-St Louis

4h 37m

1 stop

DCA9:09 pmWashington, D.C. Reagan-National

Sep 7

DCA8:30 amWashington, D.C. Reagan-National

4h 32m

1 stop

STL12:02 pmLambert-St Louis

$276

momondo Fare Finder

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

Cheapest round-trip

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Mon 9/14

2:29 pm-11:04 pm

1 stop7h 35m

Baltimore/Washington

Mon 9/21

6:00 am-1:10 pm

1 stop8h 10m

$139

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Mon 9/14

2:29 pm-11:04 pm

1 stop7h 35m

Baltimore/Washington

Mon 9/21

6:00 am-1:10 pm

1 stop8h 10m

$140

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Thu 9/3

10:44 am-2:17 pm

Nonstop2h 33m

Washington, D.C. Reagan-National

Mon 9/7

5:23 pm-12:14 am

1 stop7h 51m

$260

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Sat 9/5

1:15 pm-9:55 pm

2 stops7h 40m

Washington, D.C. Reagan-National

Sun 9/6

6:00 am-9:25 am

1 stop4h 25m

$262

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Thu 9/17

8:30 am-3:40 pm

1 stop6h 10m

Washington, D.C. Reagan-National

Sat 9/19

6:30 am-1:15 pm

2 stops7h 45m

$262

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Wed 9/2

5:30 pm-11:26 pm

1 stop4h 56m

Washington, D.C. Dulles Intl

Sun 9/6

6:00 am-9:20 am

1 stop4h 20m

$262

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Tue 9/1

6:00 am-2:05 pm

1 stop7h 05m

Washington, D.C. Dulles Intl

Sun 9/6

11:10 am-4:38 pm

1 stop6h 28m

$262

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Sat 9/5

6:54 pm-12:44 am

1 stop4h 50m

Washington, D.C. Dulles Intl

Mon 9/7

8:25 am-9:39 am

Nonstop2h 14m

$266

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Thu 11/26

8:30 am-11:40 am

Nonstop2h 10m

Washington, D.C. Dulles Intl

Wed 12/2

1:05 pm-6:06 pm

1 stop6h 01m

$266

Quickest round-trip

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Thu 11/5

7:00 am-10:08 am

Nonstop2h 08m

Washington, D.C. Reagan-National

Mon 11/9

8:25 am-10:09 am

Nonstop2h 44m

$267

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first

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

Prices

Airlines

Other information

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

Prices are currently low for flights on this route.

Typical prices usually range from $253 to $365.
The lowest price recently found on this route was $139.

What is the cheapest month to fly to Washington, D.C.?

The month of October is, on average, the cheapest month to fly to Washington, D.C. from St. Louis, with most prices found around $309. If you’re not able to fly to Washington, D.C. in October, then September is your next best option. Flight prices from St. Louis to Washington, D.C. during September average around $310.

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 $391. However, this price may fluctuate depending on the airline, the season, and holidays. When flying out on a Monday, the most expensive travel day of the week, you can expect to see flight prices from St. Louis to Washington, D.C. for around $532.

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

In the afternoon 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 $357. Flying to Washington, D.C. in the afternoon 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 $546. 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

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

There are 4 cabin classes available to choose from on 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 33% 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 August 2026, prices for St. Louis to Washington, D.C. flights are approximately 40% 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	$207
Fastest flight time	1h 50m
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 $207. The best round-trip flight deal from St. Louis to Washington, D.C. found on momondo in the last 72 hours is $317.

The fastest flight from St. Louis to Washington, D.C. takes 1h 50m

Direct flights go from St. Louis to Washington, D.C. every day.

There are 2 airports in Washington, D.C.. From St. Louis there are direct flights to Washington, D.C. Reagan-National (DCA), Baltimore/Washington (BWI), Washington, D.C. Dulles Intl (IAD).

Search flight deals

Frequently asked questions about flying from St. Louis to Washington, D.C.

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 1h 50m.
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.?
The number of operators available for flights from Lambert-St Louis Airport to Washington, D.C. is 5 as of August 2026.
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.?
Based on momondo bookings for this flight route, the most popular plane model on flight routes from St. Louis to Washington, D.C. is Boeing 737 MAX 8 (21.38% of total bookings). The next most popular plane models are Canadair (Bombardier) Regional Jet 900 (16.10%), Canadair (Bombardier) Regional Jet CRJ-550 (13.92%), and Boeing 737-800 Passenger/BBJ2 (winglets) (12.73%).
What is the most popular airline from St. Louis to Washington, D.C.?
Based on momondo bookings for flights between St. Louis and Washington, D.C., the leading airline is Southwest, making up 61% of the total bookings. Other popular airlines include American Airlines with 32%, Frontier with 5%, and United Airlines with 2%.

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
Frontier	PriceFrom $90	Free Cancellation	Rating 5.6 2,738 reviews	Search Frontier flights
Delta	PriceFrom $98	Free Cancellation	Rating 7.8 8,483 reviews	Search Delta flights
American Airlines	PriceFrom $201	Free Cancellation	Rating 7.1 11,846 reviews	Search American Airlines flights
Southwest	PriceFrom $250	Free Cancellation	Rating 8.0 4,222 reviews	Search Southwest flights
United Airlines	PriceFrom $271	Free Cancellation	Rating 7.4 10,059 reviews	Search United Airlines flights

Southwest Flights From St. Louis to Washington, D.C.
Southwest operates around 4 flights from St. Louis to Washington, D.C. every week. The average price of these flights found in the last 72 hours has been $412, but momondo users have found Southwest deals from St. Louis to Washington, D.C. from as low as $250 round-trip. Southwest has been scored 8.0/10 in 4,222 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 $271, round-trip. It should be noted that an average United Airlines flight deal for this route in this time was higher, at $462 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. 10,059 United Airlines reviews by users on momondo have scored the airline at 7.4/10.

Alexandria

National Harbor

Arlington

Gettysburg

Waldorf

Laurel

Woodbridge

Fredericksburg

Gaithersburg

Linthicum Heights

Rockville

Silver Spring

Towson

Colonial Beach

Springfield

Fairfax

Tysons

Edgewood

Bethesda

Glen Burnie

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.

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Feeling lucky

Fly into one of these airports located in Washington, D.C.

Washington, D.C. Reagan-National Airport

Washington, D.C. Dulles Intl Airport

Cheap flights from St. Louis to Washington, D.C. from $67

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 9/11. 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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Delta flights from St. Louis to Washington, D.C.

Our best Delta deals on St. Louis to Washington, D.C. flight tickets

United Airlines flights from St. Louis to Washington, D.C.

Our best United Airlines deals on St. Louis to Washington, D.C. flight tickets

momondo Fare Finder

Use the filters below to find and compare flights from St. Louis to Washington, D.C. that are best for you.

See travel insights to Washington, D.C. from

How to get the cheapest flight ticket from St. Louis to Washington, D.C.

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.?

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

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

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

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

Can stopping save me money on St. Louis to Washington, D.C. flights?

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

What is the cheapest airline that flies from Lambert-St Louis to Washington, D.C.?

What airlines fly to Washington, D.C.?

How many flights depart from St. Louis to Washington, D.C. on average per day?

How many flights depart from St. Louis to Washington, D.C. on average per week?

When to book flights from St. Louis to Washington, D.C.

Cheap St. Louis to Washington, D.C. (STL to WAS) flight deals and tips

Best Price Found

Fastest flight time

Direct flights

Airports in Washington, D.C.

Frequently asked questions about flying 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

Traveling to a place near Washington, D.C.?

Why use momondo?

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.

Get notified when prices go down

Daily price changes in your inbox - only with Price Alerts.

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.

Fly your favorite airline to Washington, D.C.

Airlines are sorted and displayed according to clicks in the past 7 days on momondo

Cabin classes currently available on flights to Washington, D.C.

List of cabin classes available on flights landing in Washington, D.C.. Availability may vary depending on flight origin and airline.

Popular cities in the United States

Popular flights according to clicks in the last 7 days on momondo

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According to popular flight searches on momondo this year

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