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

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

How long does it take to fly to St. Louis?

Flight times from Washington, D.C. to St. Louis vary, but if you’re flying out of Baltimore and flying into St. Louis (one of the most popular routes), then the duration is 2h 10m on average. Another popular route from Washington, D.C. to St. Louis is flying from Washington, D.C. to St. Louis, which will take roughly 2h 21m. Keep in mind that layovers or delays could extend your travel time.

What airlines fly to St. Louis?

Southwest, American Airlines and Frontier are the top three most popular airlines that fly to St. Louis from Washington, D.C. according to our data. Southwest is the first choice among our users, with 49% of people opting to fly with this airline when traveling to St. Louis. Keep in mind that there are 5 different airlines that fly to St. Louis on a routine basis, so you have a few additional options to choose from.

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

As of February 2026, 16 flights take off from Washington, D.C. and land in St. Louis each day. The most common flight departure time for this route is 6:00PM, with 46% of daily flights taking off in the evening.

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

As of February 2026, there are 113 flights per week flying from Washington, D.C. to St. Louis. The most common day of the week flights depart is Thu, with 18% of flights taking off on this day.

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

Prices for flights from Washington, D.C. to Lambert-St Louis Airport are updated daily.

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

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

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

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

The required travel and health documents for your Lambert-St Louis Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Lambert-St Louis Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.

$66 Cheap Flights from Washington, D.C. to St. Louis in 2026

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

Prices are currently low for flights on this route. Typical prices usually range from $300 to $461. The lowest price recently found on this route was $134.

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

Round-trip

One-way

Last minute

Direct

Cheap round-trip flights

Enter your travel dates to find the best prices.

6:05 am - 10:37 am

BWI

STL

5h 32m

1 stop

11:27 am - 12:41 am

STL

BWI

12h 14m

1 stop

$134Frontier

Wed, Mar 18 - Tue, Mar 24

5:31 am - 1:34 pm

BWI

STL

9h 03m

1 stop

11:32 am - 12:41 am

STL

BWI

12h 09m

1 stop

$146Frontier

Mon, Mar 16 - Wed, Mar 18

3:19 pm - 10:32 am

BWI

STL

20h 13m

1 stop

11:27 am - 12:41 am

STL

BWI

12h 14m

1 stop

$149Frontier

Mon, Mar 23 - Tue, Mar 31

7:30 am - 9:06 am

DCA

STL

2h 36mnonstop

9:36 am - 12:44 pm

STL

DCA

2h 08mnonstop

$268American Airlines

Thu, Mar 26 - Tue, Mar 31

3:35 pm - 6:55 pm

DCA

STL

4h 20m

1 stop

6:00 pm - 10:55 pm

STL

DCA

3h 55m

1 stop

$270Southwest

Mon, Mar 16 - Wed, Mar 18

1:00 pm - 7:55 pm

DCA

STL

7h 55m

2 stops

10:15 am - 6:10 pm

STL

DCA

6h 55m

1 stop

$271Southwest

Tue, Mar 24 - Tue, Mar 31

9:00 am - 10:28 am

IAD

STL

2h 28mnonstop

9:16 am - 5:28 pm

STL

IAD

7h 12m

1 stop

$271United Airlines

Thu, Apr 23 - Sat, Apr 25

6:09 am - 11:11 am

DCA

STL

6h 02m

1 stop

6:00 am - 9:12 am

STL

DCA

2h 12mnonstop

$272American Airlines

Tue, Mar 31 - Mon, Apr 6

9:00 am - 10:31 am

IAD

STL

2h 31mnonstop

9:10 am - 5:09 pm

STL

IAD

6h 59m

1 stop

$272United Airlines

Sat, Apr 11 - Mon, Apr 13

6:00 am - 9:46 am

IAD

STL

4h 46m

1 stop

4:21 pm - 12:27 am

STL

IAD

7h 06m

1 stop

$274Delta

Thu, Apr 9 - Fri, Apr 10

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

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

United Airlines

Apr 23

IAD9:00 amWashington, D.C. Dulles Intl

2h 28m

STL10:28 amLambert-St Louis

Apr 25

STL9:16 amLambert-St Louis

7h 12m

1 stop

IAD5:28 pmWashington, D.C. Dulles Intl

$271

United Airlines

Apr 11

IAD9:00 amWashington, D.C. Dulles Intl

2h 31m

STL10:31 amLambert-St Louis

Apr 13

STL9:10 amLambert-St Louis

6h 59m

1 stop

IAD5:09 pmWashington, D.C. Dulles Intl

$272

United Airlines

Mar 18

IAD5:35 pmWashington, D.C. Dulles Intl

7h 16m

1 stop

STL11:51 pmLambert-St Louis

Mar 28

STL12:15 pmLambert-St Louis

2h 12m

IAD3:27 pmWashington, D.C. Dulles Intl

$273

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

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

Delta

Apr 9

IAD6:00 amWashington, D.C. Dulles Intl

4h 46m

1 stop

STL9:46 amLambert-St Louis

Apr 10

STL4:21 pmLambert-St Louis

7h 06m

1 stop

IAD12:27 amWashington, D.C. Dulles Intl

$274

Delta

Apr 17

IAD6:00 amWashington, D.C. Dulles Intl

4h 42m

1 stop

STL9:42 amLambert-St Louis

Apr 19

STL6:50 pmLambert-St Louis

4h 52m

1 stop

IAD12:42 amWashington, D.C. Dulles Intl

$296

Delta

May 28

IAD6:00 amWashington, D.C. Dulles Intl

4h 29m

1 stop

STL9:29 amLambert-St Louis

Jun 2

STL9:13 amLambert-St Louis

6h 23m

1 stop

IAD4:36 pmWashington, D.C. Dulles Intl

$315

momondo Fare Finder

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

Fly from

Fly to

Route

Depart

Return

Price

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Wed 3/18

6:05 am-10:37 am

1 stop5h 32m

Lambert-St Louis

Tue 3/24

11:27 am-12:41 am

1 stop12h 14m

$134

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Mon 3/16

5:31 am-1:34 pm

1 stop9h 03m

Lambert-St Louis

Wed 3/18

11:32 am-12:41 am

1 stop12h 09m

$146

BaltimoreSt. Louis

BWI - STL

BWISTL

Baltimore/Washington

Mon 3/23

3:19 pm-10:32 am

1 stop20h 13m

Lambert-St Louis

Tue 3/31

11:27 am-12:41 am

1 stop12h 14m

$149

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Thu 3/26

7:30 am-9:06 am

Nonstop2h 36m

Lambert-St Louis

Tue 3/31

9:36 am-12:44 pm

Nonstop2h 08m

$268

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Mon 3/16

3:35 pm-6:55 pm

1 stop4h 20m

Lambert-St Louis

Wed 3/18

6:00 pm-10:55 pm

1 stop3h 55m

$270

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Tue 3/24

1:00 pm-7:55 pm

2 stops7h 55m

Lambert-St Louis

Tue 3/31

10:15 am-6:10 pm

1 stop6h 55m

$271

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Thu 4/23

9:00 am-10:28 am

Nonstop2h 28m

Lambert-St Louis

Sat 4/25

9:16 am-5:28 pm

1 stop7h 12m

$271

Washington, D.C.St. Louis

DCA - STL

DCASTL

Washington, D.C. Reagan-National

Tue 3/31

6:09 am-11:11 am

1 stop6h 02m

Lambert-St Louis

Mon 4/6

6:00 am-9:12 am

Nonstop2h 12m

$272

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Sat 4/11

9:00 am-10:31 am

Nonstop2h 31m

Lambert-St Louis

Mon 4/13

9:10 am-5:09 pm

1 stop6h 59m

$272

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Thu 4/9

6:00 am-9:46 am

1 stop4h 46m

Lambert-St Louis

Fri 4/10

4:21 pm-12:27 am

1 stop7h 06m

$274

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 Washington, D.C. 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

Prices

Airlines

Other information

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

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

In general, August is the cheapest month to fly from Washington, D.C. to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $273. The month of October is another great option to travel to St. Louis, with average flight prices from Washington, D.C. averaging around $293.

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 Saturday when prices can be found for as low as $326. 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 Sunday because tickets tend to average around $402. 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. in the evening is the least expensive time of day to depart. momondo users have found prices as low as $308 when looking at flights departing in the evening. In the afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $381 per ticket.

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

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

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

There are 4 cabin classes available to choose from on Washington, D.C. to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

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

As of February 2026, prices for Washington, D.C. to St. Louis flights are approximately 47% cheaper when compared to flights at the same time last year.

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

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

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

Best Price Found	$179
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. in the past 72 hours is $179. The best round-trip flight deal from Washington, D.C. to St. Louis found on momondo in the last 72 hours is $322.

The fastest flight from Washington, D.C. to St. Louis takes 2h 10m

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

There is 1 airport in St. Louis. From Washington, D.C. there are direct flights to Lambert-St Louis (STL).

Search flight deals

How far is Washington, D.C. to Lambert-St Louis by plane?
There are 708.3 mi between Washington, D.C. and Lambert-St Louis. 2h 10m is a normal flight duration for this route.
When did momondo last update prices for flights from Washington, D.C. to Lambert-St Louis Airport?
Prices for flights from Washington, D.C. to Lambert-St Louis Airport are updated daily.
How many operators does momondo search for flights from Washington, D.C. to Lambert-St Louis Airport?
The number of operators available for flights from Washington, D.C. to Lambert-St Louis Airport is 5 as of February 2026.
How old do you have to be to fly from Washington, D.C. to Lambert-St Louis 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 Washington, D.C. to Lambert-St Louis Airport.
What documentation or ID do you need to fly to Lambert-St Louis Airport?
The required travel and health documents for your Lambert-St Louis Airport trip may vary depending on your itinerary and personal circumstances. As a general rule, you should carry multiple documents, including a national ID card or driver's license and a passport valid for six months after your intended arrival at Lambert-St Louis Airport. We recommend that you seek guidance from your airline or a reliable third party such as IATA.
What is the most popular plane model from Washington, D.C. to St. Louis?
Based on momondo bookings for this flight route, the most popular plane model on flight routes from Washington, D.C. to St. Louis is Boeing 737 MAX 8 (19.84% of total bookings). The next most popular plane models are Boeing 737-800 Passenger/BBJ2 (winglets) (14.08%), Canadair (Bombardier) Regional Jet 700 (11.47%), and Canadair (Bombardier) Regional Jet 900 (10.98%).
What is the most popular airline from Washington, D.C. to St. Louis?
momondo data reveals that the most frequently booked airline on the route from Washington, D.C. to St. Louis is Southwest, representing 59% of all bookings. The subsequent popular airlines are American Airlines at 30%, United Airlines at 5%, and Frontier at 4%.

Best airlines flying from Washington, D.C. to St. Louis

Compare and see reviews for airlines that fly from Washington, D.C. to St. Louis with momondo

Airline	Rating	Free Cancellation	Price
Frontier	PriceFrom $78	Free Cancellation	Rating 5.7 3,040 reviews	Search Frontier flights
Delta	PriceFrom $124	Free Cancellation	Rating 7.9 8,237 reviews	Search Delta flights
American Airlines	PriceFrom $167	Free Cancellation	Rating 7.2 11,352 reviews	Search American Airlines flights
Southwest	PriceFrom $188	Free Cancellation	Rating 8.0 4,299 reviews	Search Southwest flights
United Airlines	PriceFrom $227	Free Cancellation	Rating 7.4 9,348 reviews	Search United Airlines flights

Southwest Flights From Washington, D.C. to St. Louis
Southwest operates around 20 flights from Washington, D.C. to St. Louis every week. The average price of these flights found in the last 72 hours has been $365, but momondo users have found Southwest deals from Washington, D.C. to St. Louis from as low as $188 round-trip. Southwest has been scored 8.0/10 in 4,299 reviews.
United Airlines Flights From Washington, D.C. to St. Louis
United Airlines (7.4/10 from 9,348 reviews) operates around 14 flights from Washington, D.C. to St. Louis in any given week. The average United Airlines airfare for this route is around $459, with deals from around $227 rare but found on momondo. Referenced prices are for round-trip Washington, D.C. to St. Louis flight searches in the last 72 hours.

St. Charles

Chesterfield

Hermann

Fairview Heights

Florissant

Maryland Heights

O'Fallon

St. Peters

Wentzville

Collinsville

Fenton

Alton

Farmington

Clayton

Edwardsville

Festus

Eureka

Litchfield

Glencoe

Grafton

Why use momondo?

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

To find the flight that best suits your needs, momondo gathers a range of flights from a large pool of different airlines and agents; you can then use our insights and filters to find and book the right flight to St. Louis from Washington, D.C..

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

Yes. momondo allows you to filter the results for Washington, D.C. to St. Louis flights to just show those with flexible booking policies.

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

momondo helps you find the best flight between Washington, D.C. and St. Louis by providing filters to narrow your choice of flights to those matching your criteria. You can select flights based on numerous factors such as price, departure and landing times, airport and airline.

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

If you are simply researching potential flights to St. Louis, momondo offers a useful price alert feature which will track prices for flights to St. Louis from Washington, D.C. and alert you when they change.

An easier way to manage your St. Louis trip

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Cheap flights from Washington, D.C. to St. Louis from $66

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. to St. Louis departing on 4/14. 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 Washington, D.C. to St. Louis

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

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

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

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

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

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

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

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

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

What airlines fly to St. Louis?

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

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

How long does it take to fly to St. Louis?

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

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

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

Best Price Found

Fastest flight time

Direct flights

Airports in St. Louis

Best airlines flying from Washington, D.C. to St. Louis

Compare and see reviews for airlines that fly from Washington, D.C. to St. Louis with momondo

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

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

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