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 107 per week as of March 2026. The most frequent departure day is Mon, with 18% of weekly flights leaving on this day.

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

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

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 52% 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 15 per day as of March 2026. The most frequent departure time is 8:00AM, with 48% of daily flights leaving in the afternoon.

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 March 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

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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.

8:23 pm - 11:22 am

STL

BWI

13h 59m

1 stop

9:21 pm - 6:50 am

BWI

STL

34h 29m

2 stops

$157Frontier

Mon, Apr 20 - Mon, Apr 27

8:23 pm - 8:02 am

STL

BWI

10h 39m

1 stop

5:45 pm - 11:19 pm

BWI

STL

6h 34m

1 stop

$160Frontier

Wed, Apr 15 - Sat, Apr 18

3:42 pm - 10:00 pm

STL

DCA

5h 18m

1 stop

7:59 pm - 9:25 pm

DCA

STL

2h 26mnonstop

$243American Airlines

Wed, Apr 15 - Sat, Apr 18

6:00 am - 9:15 am

STL

DCA

2h 15mnonstop

7:59 pm - 9:25 pm

DCA

STL

2h 26mnonstop

$246American Airlines

Wed, Apr 15 - Sat, Apr 18

3:10 pm - 10:45 pm

STL

DCA

6h 35m

1 stop

6:50 pm - 8:15 pm

DCA

STL

2h 25mnonstop

$247Southwest

Tue, Apr 7 - Tue, Apr 14

8:30 am - 11:43 am

STL

IAD

2h 13mnonstop

5:26 pm - 9:13 pm

IAD

STL

4h 47m

1 stop

$247United Airlines

Tue, Apr 7 - Tue, Apr 14

8:30 am - 11:42 am

STL

IAD

2h 12mnonstop

5:41 pm - 11:57 pm

IAD

STL

7h 16m

1 stop

$251United Airlines

Sat, Mar 28 - Tue, Mar 31

3:40 pm - 6:40 pm

STL

DCA

2h 00mnonstop

11:40 am - 6:00 pm

DCA

STL

7h 20m

2 stops

$252Southwest

Tue, Apr 7 - Tue, Apr 14

4:41 pm - 10:34 pm

STL

DCA

4h 53m

1 stop

6:59 am - 10:34 am

DCA

STL

4h 35m

1 stop

$253Delta

Wed, Apr 15 - Sat, Apr 18

1:27 pm - 9:24 pm

STL

IAD

6h 57m

1 stop

11:15 am - 5:16 pm

IAD

STL

7h 01m

1 stop

$253Delta

Tue, May 12 - Sat, May 16

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

Apr 7

STL8:30 amLambert-St Louis

2h 13m

IAD11:43 amWashington, D.C. Dulles Intl

Apr 14

IAD5:26 pmWashington, D.C. Dulles Intl

4h 47m

1 stop

STL9:13 pmLambert-St Louis

$247

United Airlines

Mar 28

STL8:30 amLambert-St Louis

2h 12m

IAD11:42 amWashington, D.C. Dulles Intl

Mar 31

IAD5:41 pmWashington, D.C. Dulles Intl

7h 16m

1 stop

STL11:57 pmLambert-St Louis

$251

United Airlines

Mar 28

STL7:00 pmLambert-St Louis

3h 59m

1 stop

IAD11:59 pmWashington, D.C. Dulles Intl

Mar 31

IAD5:41 pmWashington, D.C. Dulles Intl

7h 16m

1 stop

STL11:57 pmLambert-St Louis

$261

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

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

Delta

May 12

STL1:27 pmLambert-St Louis

6h 57m

1 stop

IAD9:24 pmWashington, D.C. Dulles Intl

May 16

IAD11:15 amWashington, D.C. Dulles Intl

7h 01m

1 stop

STL5:16 pmLambert-St Louis

$253

Delta

May 12

STL9:15 amLambert-St Louis

6h 21m

1 stop

IAD4:36 pmWashington, D.C. Dulles Intl

May 16

IAD12:45 pmWashington, D.C. Dulles Intl

4h 25m

1 stop

STL4:10 pmLambert-St Louis

$266

Delta

Apr 8

STL6:32 amLambert-St Louis

4h 00m

1 stop

IAD11:32 amWashington, D.C. Dulles Intl

Apr 11

IAD6:00 amWashington, D.C. Dulles Intl

4h 46m

1 stop

STL9:46 amLambert-St Louis

$274

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 4/20

8:23 pm-11:22 am

1 stop13h 59m

Baltimore/Washington

Mon 4/27

9:21 pm-6:50 am

2 stops34h 29m

$157

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Wed 4/15

8:23 pm-8:02 am

1 stop10h 39m

Baltimore/Washington

Sat 4/18

5:45 pm-11:19 pm

1 stop6h 34m

$160

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 4/15

3:42 pm-10:00 pm

1 stop5h 18m

Washington, D.C. Reagan-National

Sat 4/18

7:59 pm-9:25 pm

Nonstop2h 26m

$243

Quickest round-trip

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 4/15

6:00 am-9:15 am

Nonstop2h 15m

Washington, D.C. Reagan-National

Sat 4/18

7:59 pm-9:25 pm

Nonstop2h 26m

$246

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Tue 4/7

3:10 pm-10:45 pm

1 stop6h 35m

Washington, D.C. Reagan-National

Tue 4/14

6:50 pm-8:15 pm

Nonstop2h 25m

$247

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Tue 4/7

8:30 am-11:43 am

Nonstop2h 13m

Washington, D.C. Dulles Intl

Tue 4/14

5:26 pm-9:13 pm

1 stop4h 47m

$247

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Sat 3/28

8:30 am-11:42 am

Nonstop2h 12m

Washington, D.C. Dulles Intl

Tue 3/31

5:41 pm-11:57 pm

1 stop7h 16m

$251

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Tue 4/7

3:40 pm-6:40 pm

Nonstop2h 00m

Washington, D.C. Reagan-National

Tue 4/14

11:40 am-6:00 pm

2 stops7h 20m

$252

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 4/15

4:41 pm-10:34 pm

1 stop4h 53m

Washington, D.C. Reagan-National

Sat 4/18

6:59 am-10:34 am

1 stop4h 35m

$253

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Tue 5/12

1:27 pm-9:24 pm

1 stop6h 57m

Washington, D.C. Dulles Intl

Sat 5/16

11:15 am-5:16 pm

1 stop7h 01m

$253

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.?

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 October is your next best option. Flight prices from St. Louis to Washington, D.C. during October average around $262.

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 $362. However, this price may fluctuate depending on the airline, the season, and holidays. When flying out on a Wednesday, the most expensive travel day of the week, you can expect to see flight prices from St. Louis to Washington, D.C. for around $488.

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 $324. 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 $884. 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

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 $370 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 $188 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?

No. A direct flight is the cheapest option for a flight between St. Louis to Washington, D.C..

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

As of March 2026, prices for St. Louis to Washington, D.C. flights are approximately 49% 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	$192
Fastest flight time	1h 55m
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 $192. The best round-trip flight deal from St. Louis to Washington, D.C. found on momondo in the last 72 hours is $301.

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

Search flight deals

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 55m.
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 March 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 (23.26% of total bookings). The next most popular plane models are Canadair (Bombardier) Regional Jet 900 (14.70%), Canadair (Bombardier) Regional Jet 700 (14.41%), and Canadair (Bombardier) Regional Jet CRJ-550 (13.83%).
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 58% of the total bookings. Other popular airlines include American Airlines with 34%, Frontier with 6%, and Delta 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
Delta	PriceFrom $99	Free Cancellation	Rating 7.9 8,276 reviews	Search Delta flights
Frontier	PriceFrom $113	Free Cancellation	Rating 5.7 3,033 reviews	Search Frontier flights
American Airlines	PriceFrom $172	Free Cancellation	Rating 7.1 11,414 reviews	Search American Airlines flights
Southwest	PriceFrom $197	Free Cancellation	Rating 8.0 4,317 reviews	Search Southwest flights
United Airlines	PriceFrom $263	Free Cancellation	Rating 7.4 9,409 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 $355, but momondo users have found Southwest deals from St. Louis to Washington, D.C. from as low as $197 round-trip. Southwest has been scored 8.0/10 in 4,317 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 $263, 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. 9,409 United Airlines reviews by users on momondo have scored the airline at 7.4/10.

Alexandria

National Harbor

Gettysburg

Arlington

Waldorf

Woodbridge

Colonial Beach

Laurel

Towson

Gaithersburg

Silver Spring

Fredericksburg

Rockville

Tysons

Manassas

Springfield

Bethesda

Fairfax

Linthicum Heights

College Park

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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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 4/27. 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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United Airlines flights from St. Louis to Washington, D.C.

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

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

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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.

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?

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

What cabin class options are available on Lambert-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

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

Best Price Found

Fastest flight time

Direct flights

Airports in 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

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

United Airlines Flights From St. Louis to Washington, D.C.

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

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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.

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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.

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