How popular is this St. Louis to Washington, D.C. flight route?

This flight path from Lambert-St Louis to Washington, D.C. was viewed by 26 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

What are the cheapest airlines flying from St. Louis to Washington, D.C. round-trip?

Flying on Spirit Airlines is currently your cheapest option to Washington, D.C., with prices starting at $161. Additional round-trip tickets that might be worth considering are offered by Frontier and Southwest, with the lowest prices starting at $205 and $217, respectively. Spirit Airlines is 45% cheaper than the average price of flights available within the next 90 days to this destination.

What are the cheapest airlines to fly from St. Louis to Washington, D.C. one-way?

For one-way options, check prices for Spirit Airlines. According to our data, you can fly for as low as $64. Users have also found prices from $99 and $109 on Frontier and Southwest, respectively.

In terms of precipitation, rainfall in Washington, D.C. ranges from 2.6 - 4.0 inches per month. May is typically the wettest month, when rainfall can reach 4.0 in. February is typically the driest time to visit Washington, D.C. when rainfall is around 2.6 in.

If weather is an important factor for your trip to Washington, D.C., use this chart to help with planning. For those seeking warmer temperatures, July is the ideal time of year to visit, when temperatures reach an average of 80.6 F. Travelers looking to avoid the cold should look outside of January, when temperatures are typically at their lowest (around 35.6 F).

What are the most popular routes from St. Louis to Washington, D.C.?

The most popular route from St. Louis to Washington, D.C. is Lambert-St Louis - Washington, D.C. Dulles Intl. You may also consider Lambert-St Louis - Baltimore/Washington or Lambert-St Louis - Washington, D.C. Reagan-National.

What are the cheapest flights from St. Louis to Washington, D.C.?

While on average a flight from St. Louis to Washington, D.C. is generally $329, our data shows the cheapest flight currently is $108. When looking at the most popular route, (Lambert-St Louis - Washington, D.C. Dulles Intl), you can expect to pay $218 for that flight.

What are the most popular airlines that fly from St. Louis to Washington, D.C.?

American Airlines, Delta and Frontier are the most popular airlines when flying from St. Louis to Washington, D.C..

What is the cheapest day to fly round-trip from St. Louis to Washington, D.C.?

Flights from St. Louis to Washington, D.C. are found to be more expensive on Friday. This shouldn't discourage you from searching as you can still find great deals by being flexible with your options. Use our search form to find deals on tickets to Washington, D.C..

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

Travelers have found it’s best to book a flight 52 days in advance to save up to 232% compared to booking the same week of travel. As your travel date approaches, the cost of this flight route may potentially increase. While opting to book 52 days out may not be an option for all, there are still additional ways to secure a deal in the near future. You might find a flight from St. Louis to Washington, D.C. 1-2 weeks in advance for as low as $425, or $582 for flights within the next 24 hours.

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

Due to multiple factors, expect to potentially pay more when booking in March. For low rates, August can be a great choice for travel to Washington, D.C.. Flights to Washington, D.C. from St. Louis in August are about $297 on average during August, but can be found for as low as $149.

What airport do you fly from for flights from St. Louis to Washington, D.C.?

If you book a flight to Washington, D.C. from St. Louis, you will be flying from Lambert-St Louis, which is the city’s only airport. Lambert-St Louis (STL) is located 12.7 mi from the center of St. Louis. There are 11 flights from Lambert-St Louis to Washington, D.C. per day from 5 different airlines.

Can I find deals for flights from St. Louis to Washington, D.C. that include hotel bookings?

Yes. In addition to deals on St. Louis to Washington, D.C. flights, Cheapflights offers vacation packages that include both flights and hotel.

How can I find direct flights from St. Louis to Washington, D.C.?

After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Washington, D.C..

Can I find deals for business class flights from St. Louis to Washington, D.C.?

Yes. Cheapflights offers flight deals from St. Louis to Washington, D.C. by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

$64+ Flights from St. Louis to Washington, D.C.

Q: How much does it cost to fly round-trip from St. Louis to Washington, D.C.?

Airfare is below average for this route at the moment. St. Louis to Washington, D.C. flights typically cost between $201 and $329 in August. The cheapest round-trip price found within the last 3 days was $161 on Spirit Airlines (Aug 22-Aug 24).

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Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

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3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheapflights Tip: The best prices from Lambert-St Louis to Washington, D.C. are usually found in August or November, booked 51 days in advance, depart on a Friday or Tuesday and return on a Wednesday

Cheap flight deals from St. Louis to Washington, D.C.

Round-trip from	$161 (FlightHub)
One-way from	$64 (Cheapflightsfares)
Popular in	March
Cheapest in	August
Average price	$309
Good round-trip deal	$212 or less
Good one-way deal	$125 or less

From Lambert-St Louis to Washington, D.C. (WAS)

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One-way flight from Lambert-St Louis to Washington, D.C. (WAS)

Search Deals

Highest demand for flights based on searches. 10% potential increase in price ($32 potential increase over avg. RT price).

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Cheapest flight prices on average. 2% potential price decrease ($9 potential savings vs. average RT price).

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Average for round-trip flights in July 2025

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Price to beat on a round-trip flight from Lambert-St Louis to Washington, D.C. (WAS).

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Price to beat on a one-way flight from Lambert-St Louis to Washington, D.C. (WAS).

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Find flight deals from St. Louis to Washington, D.C.

Cheapest flights from St. Louis to Washington, D.C.
Explore the most affordable flight options available from St. Louis to Washington, D.C.. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 31, 2025.

Fri 8/222:30 pmSTL - BWI

1 stop6h 39mSpirit Airlines

Sun 8/242:30 pmBWI - STL

1 stop24h 02mSpirit Airlines

Deal found 7/30

$161

Sat 8/22:52 pmSTL - IAD

1 stop7h 27mFrontier

Sat 8/96:10 amIAD - STL

1 stop8h 49mFrontier

Deal found 7/30

$198

Sat 8/22:52 pmSTL - BWI

1 stop8h 03mFrontier

Sat 8/97:15 amBWI - STL

1 stop7h 44mFrontier

Deal found 7/30

$205

Thu 9/412:05 pmSTL - BWI

1 stop9h 23mMultiple Airlines

Mon 9/86:22 amBWI - STL

1 stop9h 42mMultiple Airlines

Deal found 7/29

$213

Thu 8/287:25 pmSTL - DCA

Nonstop2h 05mSouthwest

Thu 9/46:50 pmDCA - STL

Nonstop2h 10mSouthwest

Deal found 7/31

$217

Sat 8/3010:30 amSTL - BWI

1 stop3h 20mSouthwest

Sat 9/66:35 amBWI - STL

Nonstop2h 10mSouthwest

Deal found 7/31

$223

Wed 8/277:54 pmSTL - DCA

1 stop15h 17mFrontier

Wed 9/31:00 pmDCA - STL

1 stop21h 06mFrontier

Deal found 7/30

$225

Wed 8/276:40 amSTL - BWI

1 stop3h 58mDelta

Wed 9/31:35 pmBWI - STL

1 stop6h 32mDelta

Deal found 7/30

$227

Wed 8/276:35 amSTL - IAD

1 stop4h 20mUnited Airlines

Sat 9/68:40 amIAD - STL

Nonstop2h 22mUnited Airlines

Deal found 7/31

$227

Wed 11/127:00 amSTL - DCA

1 stop4h 34mUnited Airlines

Wed 11/125:00 pmDCA - STL

1 stop6h 45mUnited Airlines

Deal found 7/30

$232

Wed 9/249:57 amSTL - BWI

1 stop6h 44mAmerican Airlines

Mon 9/296:20 pmBWI - STL

1 stop6h 28mAmerican Airlines

Deal found 7/30

$232

Sat 8/236:02 amSTL - DCA

Nonstop2h 01mAmerican Airlines

Mon 8/252:56 pmDCA - STL

Nonstop2h 18mAmerican Airlines

Deal found 7/30

$233

Best flights from St. Louis to Washington, D.C.
Discover carefully curated flight deals from St. Louis to Washington, D.C. that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated July 31, 2025.

Fri 8/222:30 pmSTL - BWI

1 stop6h 39mSpirit Airlines

Sun 8/242:30 pmBWI - STL

1 stop24h 02mSpirit Airlines

Deal found 7/30

$161

Tue 8/125:40 pmSTL - BWI

1 stop16h 18mFrontier

Sat 8/1612:23 pmBWI - STL

1 stop12h 24mFrontier

Deal found 7/30

$205

Thu 9/412:05 pmSTL - BWI

1 stop9h 23mMultiple Airlines

Mon 9/86:22 amBWI - STL

1 stop9h 42mMultiple Airlines

Deal found 7/29

$213

Thu 8/287:25 pmSTL - DCA

Nonstop2h 05mSouthwest

Thu 9/46:50 pmDCA - STL

Nonstop2h 10mSouthwest

Deal found 7/31

$217

Wed 8/276:40 amSTL - BWI

1 stop3h 58mDelta

Wed 9/31:35 pmBWI - STL

1 stop6h 32mDelta

Deal found 7/30

$227

Wed 8/276:35 amSTL - IAD

1 stop4h 20mUnited Airlines

Sat 9/68:40 amIAD - STL

Nonstop2h 22mUnited Airlines

Deal found 7/31

$227

Wed 9/249:57 amSTL - BWI

1 stop6h 44mAmerican Airlines

Mon 9/296:20 pmBWI - STL

1 stop6h 28mAmerican Airlines

Deal found 7/30

$232

Sat 8/303:02 pmSTL - IAD

1 stop6h 58mFrontier

Mon 9/16:10 amIAD - STL

1 stop7h 46mFrontier

Deal found 7/31

$208

Sat 8/3010:30 amSTL - BWI

1 stop3h 20mSouthwest

Sat 9/66:35 amBWI - STL

Nonstop2h 10mSouthwest

Deal found 7/31

$223

Wed 11/127:00 amSTL - DCA

1 stop4h 34mUnited Airlines

Wed 11/125:00 pmDCA - STL

1 stop6h 45mUnited Airlines

Deal found 7/30

$232

Sat 8/236:02 amSTL - DCA

Nonstop2h 01mAmerican Airlines

Mon 8/252:56 pmDCA - STL

Nonstop2h 18mAmerican Airlines

Deal found 7/30

$233

Tue 8/266:40 amSTL - DCA

1 stop3h 54mDelta

Tue 8/266:20 pmDCA - STL

1 stop4h 42mDelta

Deal found 7/30

$237

Last-minute flights from St. Louis to Washington, D.C.
Discover last-minute flight deals from St. Louis to Washington, D.C.. Data last updated July 31, 2025 and is based on user searches.

Sat 8/22:52 pmSTL - IAD

1 stop7h 27mFrontier

Sat 8/96:10 amIAD - STL

1 stop8h 49mFrontier

Deal found 7/30

$198

Sat 8/22:52 pmSTL - BWI

1 stop8h 03mFrontier

Sat 8/97:15 amBWI - STL

1 stop7h 44mFrontier

Deal found 7/30

$205

Tue 8/59:09 amSTL - IAD

1 stop13h 49mAmerican Airlines

Tue 8/124:36 pmIAD - STL

1 stop17h 53mAmerican Airlines

Deal found 7/31

$550

Wed 8/67:29 pmSTL - DCA

1 stop15h 35mFrontier

Sat 10/186:00 pmDCA - STL

1 stop16h 07mFrontier

Deal found 7/30

$225

Wed 8/611:24 amSTL - BWI

1 stop11h 25mSpirit Airlines

Sat 10/186:45 amBWI - STL

1 stop12h 10mSpirit Airlines

Deal found 7/30

$248

Wed 8/65:52 pmSTL - DCA

Nonstop2h 01mAmerican Airlines

Sat 10/186:00 pmDCA - STL

Nonstop2h 28mAmerican Airlines

Deal found 7/30

$424

Wed 8/66:50 pmSTL - BWI

Nonstop2h 00mSouthwest

Sat 10/187:10 pmBWI - STL

Nonstop2h 20mSouthwest

Deal found 7/30

$424

Wed 8/68:15 amSTL - IAD

Nonstop2h 08mUnited Airlines

Sat 10/186:30 amIAD - STL

1 stop5h 19mUnited Airlines

Deal found 7/30

$434

Thu 8/72:36 pmSTL - BWI

1 stop8h 49mFrontier

Sat 8/167:15 amBWI - STL

1 stop7h 44mFrontier

Deal found 7/31

$208

Thu 8/72:15 pmSTL - DCA

1 stop3h 44mDelta

Sat 8/1612:29 pmDCA - STL

1 stop5h 06mDelta

Deal found 7/31

$511

Fri 8/89:50 amSTL - DCA

2 stops7h 20mSouthwest

Sat 8/306:00 amDCA - STL

2 stops9h 15mSouthwest

Deal found 7/30

$454

Sat 8/92:52 pmSTL - IAD

1 stop7h 34mFrontier

Thu 8/146:10 amIAD - STL

1 stop8h 24mFrontier

Deal found 7/31

$208

One-way flights from St. Louis to Washington, D.C.
Search for one-way flight options from St. Louis to Washington, D.C.. Find affordable one-way fares based on user searches. Data last updated July 31, 2025.

Sun 8/312:30 pmSTL - BWI

1 stop6h 39mSpirit Airlines

Deal found 7/30

$64

Sat 8/92:52 pmSTL - IAD

1 stop7h 34mFrontier

Deal found 7/30

$99

Sat 8/92:52 pmSTL - BWI

1 stop8h 07mFrontier

Deal found 7/30

$105

Thu 8/287:25 pmSTL - DCA

Nonstop2h 05mSouthwest

Deal found 7/31

$109

Mon 9/294:15 pmSTL - BWI

Nonstop2h 00mSouthwest

Deal found 7/31

$109

Tue 12/164:39 pmSTL - BWI

1 stop4h 01mAmerican Airlines

Deal found 7/30

$113

Tue 9/307:10 amSTL - BWI

1 stop4h 35mDelta

Deal found 7/30

$114

Sat 8/307:54 pmSTL - DCA

1 stop20h 05mFrontier

Deal found 7/31

$116

Wed 12/172:18 pmSTL - DCA

1 stop4h 02mDelta

Deal found 7/31

$119

Wed 11/56:40 amSTL - IAD

1 stop3h 49mDelta

Deal found 7/30

$119

Sat 11/88:25 amSTL - IAD

Nonstop2h 08mUnited Airlines

Deal found 7/31

$121

Thu 12/46:21 amSTL - DCA

Nonstop2h 08mAmerican Airlines

Deal found 7/30

$125

Cheapflights 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

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Fri 8/22

2:30 pm-10:09 pm

1 stop6h 39m

Baltimore/Washington

Sun 8/24

2:30 pm-1:32 pm

1 stop24h 02m

$161

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Tue 8/12

5:40 pm-10:58 am

1 stop16h 18m

Baltimore/Washington

Sat 8/16

12:23 pm-11:47 pm

1 stop12h 24m

$205

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Sat 8/30

3:02 pm-11:00 pm

1 stop6h 58m

Washington, D.C. Dulles Intl

Mon 9/1

6:10 am-12:56 pm

1 stop7h 46m

$208

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Thu 9/4

12:05 pm-10:28 pm

1 stop9h 23m

Baltimore/Washington

Mon 9/8

6:22 am-3:04 pm

1 stop9h 42m

$213

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Thu 8/28

7:25 pm-10:30 pm

Nonstop2h 05m

Washington, D.C. Reagan-National

Thu 9/4

6:50 pm-8:00 pm

Nonstop2h 10m

$217

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Sat 8/30

10:30 am-2:50 pm

1 stop3h 20m

Baltimore/Washington

Sat 9/6

6:35 am-7:45 am

Nonstop2h 10m

$223

St. LouisWashington, D.C.

STL - DCA

STLDCA

Lambert-St Louis

Wed 8/27

7:54 pm-12:11 pm

1 stop15h 17m

Washington, D.C. Reagan-National

Wed 9/3

1:00 pm-9:06 am

1 stop21h 06m

$225

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Wed 8/27

6:40 am-11:38 am

1 stop3h 58m

Baltimore/Washington

Wed 9/3

1:35 pm-7:07 pm

1 stop6h 32m

$227

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Wed 8/27

6:35 am-11:55 am

1 stop4h 20m

Washington, D.C. Dulles Intl

Sat 9/6

8:40 am-10:02 am

Nonstop2h 22m

$227

St. LouisBaltimore

STL - BWI

STLBWI

Lambert-St Louis

Wed 9/24

9:57 am-5:41 pm

1 stop6h 44m

Baltimore/Washington

Mon 9/29

6:20 pm-11:48 pm

1 stop6h 28m

$232

Flights are sorted by cheapest round-trip flights first.

Deals found on 7/30

Showing 1-10 of 32 results

The best insider tips for St. Louis to Washington, D.C. flights

Cheapflights partnered with top experts to bring you the best recommendations for your St. Louis to Washington, D.C. trip

Airlines

Southwest

Enjoy free snacks and non-alcoholic drinks, plus Wi-Fi for a fee on board.

Two free checked bags included, even oversized like skis or golf clubs.

Read more about Southwestby Marisa Garcia

United Airlines

Basic Economy allows a personal item only; no carry-on bags permitted.

Economy Plus offers extra legroom seats towards the front of the cabin.

Read more about United Airlinesby Harriet Baskas

Airports

STL

Security lines at STL are generally quick, averaging 5 to 10 minutes during off-peak times. Check real-time wait times online before heading to the airport.

DCA

DCA is easily accessible via the Metro, with a dedicated stop on the Yellow and Blue lines. It's the most affordable option for reaching downtown D.C.

IAD

The Silver Line Metro now reaches IAD in under 40 minutes, making it a cost-effective way to travel to and from the airport.

Our travel experts

Marisa Garcia

Expert on Southwest

Harriet Baskas

Expert on United Airlines

Emily Zemler

Expert on DCA

Taryn White

Expert on STL

Ramsey Qubein

Expert on IAD

Best time to book a flight from St. Louis to Washington, D.C.

Have a flexible travel schedule? Discover the best time to fly to Washington, D.C. from St. Louis with our price prediction graph.

Estimated round-trip price

Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from St. Louis to Washington, D.C.

How far ahead should I book a flight from St. Louis to Washington, D.C.?

Booking 51 days in advance of your planned departure date is, on average, the best time to get cheap flights from St. Louis to Washington, D.C.. The general trend is that the closer you book to the departure date, the more expensive your flight will be.

What is the cheapest month to book a flight from St. Louis to Washington, D.C.?

Currently, August is the cheapest month in which you can book a flight from St. Louis to Washington, D.C. (average of $241). Flying from St. Louis to Washington, D.C. in March is currently the most expensive (average of $290). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from STL to WAS?

It’s typically best to fly out from St. Louis to Washington, D.C. in the evening. Doing so could potentially save you 72% on the flight price compared to flying at noon, which is usually more expensive.

What is the cheapest day to fly from St. Louis to Washington, D.C.?

Travelers seeking maximum savings on their St. Louis to Washington, D.C. flight should consider departing on Friday evenings when fares are most often at their lowest. Sunday at noon flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from St. Louis to Washington, D.C.

The most flights from STL to WAS are scheduled on a Monday (16 on average). You will have fewer flight options on Wednesday, which is when the least amount of flights are scheduled (7 on average).

How much does it cost to fly round-trip from St. Louis to Washington, D.C.?

What’s the top layover airport for flights from St. Louis to Washington, D.C.?

Chicago (ORD) – chosen by Cheapflights users on 50% of 1-stop itineraries from St. Louis to Washington, D.C. on Cheapflights.

What’s the cheapest layover airport for flights from St. Louis to Washington, D.C.?

Denver (DEN) is the most affordable 1-stop option, with an average round-trip price of $294.

What’s the fastest layover option from St. Louis to Washington, D.C.?

Flights via Chicago (ORD) have the shortest average one-way travel time for 1-stop routes: 4h 56m.

Which airport typically offers the quickest layover for flights from St. Louis to Washington, D.C.?

Flights via Chicago (ORD) offer the fastest connection on this route, with an average layover time of 1h 28m.

Reviews of airlines servicing Washington, D.C.

Get a feel of what it's like to fly with Southwest, Delta, and United Airlines from St. Louis to Washington, D.C. by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Southwest

8.0

Very good

4,246 reviews

Reviews

1 / 20

8.0

Excellent

Gina,Jul 2025

LAS - DEN

We experienced bad weather, which turned our 1.5 hour flight from Las Vegas to Denver, into 3.5. The pilot and crew kept us updated and explained that we had to circle and or possibly redirect to another airport. After circling for sometime, we were able to land smoothly in Denver. Thank you to all the flight crew, tower control, and all who got us to our destination safely.

Southwest

8.0

Very good

4,246 reviews

Southwest

8.0

Very good

4,246 reviews

Reviews

1 / 20

8.0

Excellent

Gina,Jul 2025

LAS - DEN

Delta

8.0

Very good

7,981 reviews

Southwest

8.0

Very good

4,246 reviews

Reviews

1 / 20

8.0

Excellent

Gina,Jul 2025

LAS - DEN

United Airlines

7.4

Good

8,900 reviews

Southwest

8.0

Very good

4,246 reviews

Reviews

1 / 20

8.0

Excellent

Gina,Jul 2025

LAS - DEN

American Airlines

7.2

Good

10,000 reviews

Southwest

8.0

Very good

4,246 reviews

Reviews

1 / 20

8.0

Excellent

Gina,Jul 2025

LAS - DEN

Spirit Airlines

6.3

Okay

8,049 reviews

Southwest

8.0

Very good

4,246 reviews

Reviews

1 / 20

8.0

Excellent

Gina,Jul 2025

LAS - DEN

Related info for your journey

What airport do you fly from for flights from St. Louis to Washington, D.C.?
If you book a flight to Washington, D.C. from St. Louis, you will be flying from Lambert-St Louis, which is the city’s only airport. Lambert-St Louis (STL) is located 12.7 mi from the center of St. Louis. There are 11 flights from Lambert-St Louis to Washington, D.C. per day from 5 different airlines.
How popular is this St. Louis to Washington, D.C. flight route?
This flight path from Lambert-St Louis to Washington, D.C. was viewed by 26 users in the past month. Keep an eye out for changes in search interest prior to high and low season.
What are the cheapest airlines flying from St. Louis to Washington, D.C. round-trip?
Flying on Spirit Airlines is currently your cheapest option to Washington, D.C., with prices starting at $161. Additional round-trip tickets that might be worth considering are offered by Frontier and Southwest, with the lowest prices starting at $205 and $217, respectively. Spirit Airlines is 45% cheaper than the average price of flights available within the next 90 days to this destination.
What are the cheapest airlines to fly from St. Louis to Washington, D.C. one-way?
For one-way options, check prices for Spirit Airlines. According to our data, you can fly for as low as $64. Users have also found prices from $99 and $109 on Frontier and Southwest, respectively.
What are the most popular routes from St. Louis to Washington, D.C.?
The most popular route from St. Louis to Washington, D.C. is Lambert-St Louis - Washington, D.C. Dulles Intl. You may also consider Lambert-St Louis - Baltimore/Washington or Lambert-St Louis - Washington, D.C. Reagan-National.
What are the cheapest flights from St. Louis to Washington, D.C.?
While on average a flight from St. Louis to Washington, D.C. is generally $329, our data shows the cheapest flight currently is $108. When looking at the most popular route, (Lambert-St Louis - Washington, D.C. Dulles Intl), you can expect to pay $218 for that flight.
Can I find deals for flights from St. Louis to Washington, D.C. that include hotel bookings?
Yes. In addition to deals on St. Louis to Washington, D.C. flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from St. Louis to Washington, D.C.?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Washington, D.C..
Can I find deals for business class flights from St. Louis to Washington, D.C.?
Yes. Cheapflights offers flight deals from St. Louis to Washington, D.C. by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.
What is the cheapest month to book a flight from St. Louis to Washington, D.C.?
Currently, August is the cheapest month in which you can book a flight from St. Louis to Washington, D.C. (average of $241). Flying from St. Louis to Washington, D.C. in March is currently the most expensive (average of $290). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

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Top 5 airlines flying from St. Louis to Washington, D.C.

Airline	Cheapest	Average	Flexibility	On-time
Frontier	Cheapest$124	Average$221	FlexibilityNo cancel fee	On-time62%
American Airlines	Cheapest$129	Average$357	FlexibilityNo cancel fee	On-time71%
Delta	Cheapest$168	Average$276	FlexibilityNo cancel fee	On-timeN/A
Southwest	Cheapest$190	Average$333	FlexibilityNo cancel fee	On-time63%
United Airlines	Cheapest$209	Average$378	FlexibilityNo cancel fee	On-time69%

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$64+ Cheap flights from St. Louis (STL) to Washington, D.C. (WAS)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 8/31. Fares are subject to change and may not be available on all flights or dates of travel.

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Cheapflights Tip: The best prices from Lambert-St Louis to Washington, D.C. are usually found in August or November, booked 51 days in advance, depart on a Friday or Tuesday and return on a Wednesday

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Cheapest flights from St. Louis to Washington, D.C.Explore the most affordable flight options available from St. Louis to Washington, D.C.. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 31, 2025.

Explore the most affordable flight options available from St. Louis to Washington, D.C.. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 31, 2025.

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The best insider tips for St. Louis to Washington, D.C. flights

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Best time to book a flight from St. Louis to Washington, D.C.

Have a flexible travel schedule? Discover the best time to fly to Washington, D.C. from St. Louis with our price prediction graph.

Cheapflights Insights

Everything you need to know about your flight from St. Louis to Washington, D.C.

How far ahead should I book a flight from St. Louis to Washington, D.C.?

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Washington, D.C.. Price data was last updated on July 25, 2025.

What is the cheapest month to book a flight from St. Louis to Washington, D.C.?

What is the cheapest time of day to fly from STL to WAS?

Find hourly flight availability from St. Louis to Washington, D.C.. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated July 31, 2025.

What is the cheapest day to fly from St. Louis to Washington, D.C.?

Use this chart to determine the cheapest time to fly round-trip from St. Louis to Washington, D.C.. Price data was last updated on July 27, 2025.

Weekly flight availability from St. Louis to Washington, D.C.

How much does it cost to fly round-trip from St. Louis to Washington, D.C.?

What’s the top layover airport for flights from St. Louis to Washington, D.C.?

Share of 1-stop round-trip flights from St. Louis to Washington, D.C. chosen by Cheapflights users in the past 12 months, using the same layover each way.

What’s the cheapest layover airport for flights from St. Louis to Washington, D.C.?

Average round-trip fare for 1-stop flights from St. Louis to Washington, D.C., chosen by Cheapflights users in the past 12 months, with the same layover each way.

What’s the fastest layover option from St. Louis to Washington, D.C.?

Shortest average travel time for 1-stop one-way flights from St. Louis to Washington, D.C., based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.

Which airport typically offers the quickest layover for flights from St. Louis to Washington, D.C.?

Average layover duration for 1-stop one-way flights from St. Louis to Washington, D.C., chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Reviews of airlines servicing Washington, D.C.

Get a feel of what it's like to fly with Southwest, Delta, and United Airlines from St. Louis to Washington, D.C. by reading reviews from past customers. Users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Washington, D.C.. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

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What are the most popular routes from St. Louis to Washington, D.C.?

What are the cheapest flights from St. Louis to Washington, D.C.?

Can I find deals for flights from St. Louis to Washington, D.C. that include hotel bookings?

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What is the cheapest month to book a flight from St. Louis to Washington, D.C.?

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Top 5 airlines flying from St. Louis to Washington, D.C.

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Cheapest flights from St. Louis to Washington, D.C.
Explore the most affordable flight options available from St. Louis to Washington, D.C.. Find the lowest fares from popular airlines and budget airlines, with prices last updated on July 31, 2025.