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

Currently priced at $204, United Airlines will fly you from St. Louis to Washington, D.C. Dulles Intl Airport and back. In addition to United Airlines, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Frontier and Delta - these airlines can fly you to your destination from $208 and $224, respectively. United Airlines is 46% 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. Dulles Intl Airport one-way?

To fly one-way, consider booking your trip with Delta, which is currently one of the cheapest options available, starting at $100. Frontier flights start at $110 while deals on United Airlines start at $115 one-way.

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

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

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

On average you can expect to pay $1,212 for a flight from St. Louis to Washington, D.C. Dulles Intl Airport. The cheapest flight overall is $148 while the most popular route, (Lambert-St Louis - Washington, D.C. Dulles Intl) is currently priced at $199.

What are the most reliable airlines from St. Louis to Washington, D.C. Dulles Intl Airport?

No one likes to see their flight delayed. When booking a flight from St. Louis to Washington, D.C. Dulles Intl Airport consider choosing GoJet (82%), Avianca (82%) or Copa Airlines (82%) as they are the most reliable in getting you off to your destination on time.

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

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

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

Flights from St. Louis to Washington, D.C. Dulles Intl Airport 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. Dulles Intl Airport.

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

Due to multiple factors, expect to potentially pay more when booking in March. For low rates, November can be a great choice for travel to Washington, D.C. Dulles Intl Airport. Flights to Washington, D.C. Dulles Intl Airport from St. Louis in November are about $298 on average during November, but can be found for as low as $137.

Most accurate provider : When it comes to deals on St. Louis-Washington, D.C. Dulles Intl Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Washington, D.C. Dulles Intl Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Washington, D.C. Dulles Intl Airport flight searches over the past month and is updated monthly.

Most trusted provider : When it comes to deals on St. Louis-Washington, D.C. Dulles Intl Airport flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Washington, D.C. Dulles Intl Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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

Most people fly from Lambert-St Louis (STL) if they book a flight from St. Louis to Washington, D.C. Dulles Intl. On average, Lambert-St Louis has 3 outbound flights to Washington, D.C. Dulles Intl per day from 3 airlines. Lambert-St Louis is conveniently located just 12.7 mi from St. Louis’s city center.

Can I find deals for flights from St. Louis to Dulles Intl that include hotel bookings?

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

How can I find direct flights from St. Louis to Dulles Intl?

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

Can I find deals for business class flights from St. Louis to Dulles Intl?

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

$100+ Flights from St. Louis to Washington, D.C. Dulles Intl Airport - Compare & Save Big

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1. Tell us where you want to go

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

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

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. Dulles Intl are usually found in January or March, booked 75 days in advance, depart on a Friday or Tuesday and return on a Wednesday

Cheap flight deals from St. Louis to Dulles Intl

Most accurate provider	FlightHub 3 stars
Most trusted provider	eDreams 3 stars
Round-trip from	$204 (United Airlines)
One-way from	$100 (Delta)
Popular in	July
Cheapest in	January
Average price	$382
Good round-trip deal	$862 or less
Good one-way deal	$204 or less

Provider with most accurate pricing for Lambert-St Louis-Washington, D.C. Dulles Intl flight deals.

Search Deals

Provider most trusted by Cheapflights users for Lambert-St Louis-Washington, D.C. Dulles Intl flights.

Search Deals

From Lambert-St Louis to Washington, D.C. Dulles Intl

Search Deals

One-way flight from Lambert-St Louis to Washington, D.C. Dulles Intl

Search Deals

Highest demand for flights based on searches. 10% potential increase in price ($45 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 3% potential price decrease ($14 potential savings vs. average RT price).

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Average for round-trip flights in April 2025

Search Deals

Price to beat on a round-trip flight from Lambert-St Louis to Washington, D.C. Dulles Intl.

Search Deals

Price to beat on a one-way flight from Lambert-St Louis to Washington, D.C. Dulles Intl.

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Find flight deals from St. Louis to Dulles Intl

Cheapest flights from St. Louis to Dulles Intl
Explore the most affordable flight options available from St. Louis to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 29, 2025.

Fri 5/305:27 pmSTL - IAD

1 stop6h 03mUnited Airlines

Sat 5/318:40 amIAD - STL

Nonstop2h 16mUnited Airlines

Deal found 4/28

$204

Wed 5/215:45 pmSTL - IAD

1 stop17h 47mFrontier

Sat 5/2411:02 amIAD - STL

1 stop13h 42mFrontier

Deal found 4/28

$208

Sat 5/245:40 pmSTL - IAD

1 stop4h 55mDelta

Mon 5/266:00 amIAD - STL

1 stop4h 00mDelta

Deal found 4/28

$224

Sat 5/316:47 pmSTL - IAD

1 stop4h 15mAmerican Airlines

Tue 6/35:26 pmIAD - STL

1 stop5h 00mAmerican Airlines

Deal found 4/28

$251

Thu 7/248:44 amSTL - IAD

3 stops34h 53mMultiple Airlines

Sun 7/2711:58 amIAD - STL

2 stops7h 43mMultiple Airlines

Deal found 4/28

$440

Best flights from St. Louis to Dulles Intl
Discover carefully curated flight deals from St. Louis to Dulles Intl that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated April 29, 2025.

Fri 5/305:27 pmSTL - IAD

1 stop6h 03mUnited Airlines

Sat 5/318:40 amIAD - STL

Nonstop2h 16mUnited Airlines

Deal found 4/28

$204

Wed 5/215:45 pmSTL - IAD

1 stop17h 47mFrontier

Sat 5/2411:02 amIAD - STL

1 stop13h 42mFrontier

Deal found 4/28

$208

Sat 5/245:40 pmSTL - IAD

1 stop4h 55mDelta

Mon 5/266:00 amIAD - STL

1 stop4h 00mDelta

Deal found 4/28

$224

Sat 5/316:47 pmSTL - IAD

1 stop4h 15mAmerican Airlines

Sat 6/75:41 pmIAD - STL

1 stop7h 18mAmerican Airlines

Deal found 4/28

$251

Fri 5/309:50 amSTL - IAD

2 stops27h 54mMultiple Airlines

Sat 5/319:55 pmIAD - STL

2 stops21h 46mMultiple Airlines

Deal found 4/28

$387

Last-minute flights from St. Louis to Dulles Intl
Discover last-minute flight deals from St. Louis to Dulles Intl. Data last updated April 29, 2025 and is based on user searches.

Sat 5/39:50 amSTL - IAD

3 stops24h 57mMultiple Airlines

Thu 5/812:49 pmIAD - STL

3 stops32h 21mMultiple Airlines

Deal found 4/28

$734

Tue 5/61:00 pmSTL - IAD

Nonstop2h 09mUnited Airlines

Wed 5/148:35 amIAD - STL

Nonstop2h 23mUnited Airlines

Deal found 4/26

$399

Tue 5/65:32 pmSTL - IAD

1 stop5h 53mDelta

Wed 5/1412:39 pmIAD - STL

1 stop4h 56mDelta

Deal found 4/26

$419

Tue 5/61:59 pmSTL - IAD

1 stop4h 33mAmerican Airlines

Tue 5/131:59 pmIAD - STL

2 stops9h 20mAmerican Airlines

Deal found 4/27

$582

Wed 5/75:45 pmSTL - IAD

1 stop21h 51mFrontier

Mon 5/195:26 pmIAD - STL

1 stop7h 40mFrontier

Deal found 4/26

$210

Tue 5/207:05 amSTL - IAD

1 stop6h 37mDelta

Tue 7/110:07 amIAD - STL

1 stop5h 30mDelta

Deal found 4/27

$224

Wed 5/215:45 pmSTL - IAD

1 stop17h 47mFrontier

Sat 5/2411:02 amIAD - STL

1 stop13h 42mFrontier

Deal found 4/28

$208

Sun 5/2510:20 amSTL - IAD

1 stop24h 33mMultiple Airlines

Sun 6/111:54 amIAD - STL

2 stops7h 47mMultiple Airlines

Deal found 4/27

$329

Fri 5/305:27 pmSTL - IAD

1 stop6h 03mUnited Airlines

Sat 5/318:40 amIAD - STL

Nonstop2h 16mUnited Airlines

Deal found 4/28

$204

Sat 5/316:47 pmSTL - IAD

1 stop4h 15mAmerican Airlines

Tue 6/35:26 pmIAD - STL

1 stop5h 00mAmerican Airlines

Deal found 4/28

$251

One-way flights from St. Louis to Dulles Intl
Search for one-way flight options from St. Louis to Dulles Intl. Find affordable one-way fares based on user searches. Data last updated April 29, 2025.

Wed 5/283:40 pmSTL - IAD

1 stop4h 54mDelta

Deal found 4/28

$100

Sat 5/315:35 pmSTL - IAD

1 stop18h 14mFrontier

Deal found 4/28

$110

Sun 6/298:15 amSTL - IAD

Nonstop2h 08mUnited Airlines

Deal found 4/28

$115

Sat 5/249:50 amSTL - IAD

2 stops24h 14mMultiple Airlines

Deal found 4/28

$143

Wed 7/26:00 amSTL - IAD

2 stops10h 11mAmerican Airlines

Deal found 4/28

$223

Cheapflights Fare Finder

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

Fly from

Fly to

Route

Depart

Return

Price

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Fri 5/30

5:27 pm-12:30 am

1 stop6h 03m

Washington, D.C. Dulles Intl

Sat 5/31

8:40 am-9:56 am

Nonstop2h 16m

$204

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Wed 5/21

5:45 pm-12:32 pm

1 stop17h 47m

Washington, D.C. Dulles Intl

Sat 5/24

11:02 am-11:44 pm

1 stop13h 42m

$208

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Sat 5/24

5:40 pm-11:35 pm

1 stop4h 55m

Washington, D.C. Dulles Intl

Mon 5/26

6:00 am-9:00 am

1 stop4h 00m

$224

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Sat 5/31

6:47 pm-12:02 am

1 stop4h 15m

Washington, D.C. Dulles Intl

Tue 6/3

5:26 pm-9:26 pm

1 stop5h 00m

$251

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Fri 5/30

9:50 am-2:44 pm

2 stops27h 54m

Washington, D.C. Dulles Intl

Sat 5/31

9:55 pm-6:41 pm

2 stops21h 46m

$387

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Wed 5/28

6:30 am-11:55 am

1 stop4h 25m

$100

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Sat 5/31

5:35 pm-12:49 pm

1 stop18h 14m

$110

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Tue 6/3

3:40 pm-9:34 pm

1 stop4h 54m

$125

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Sat 5/24

9:50 am-11:04 am

2 stops24h 14m

$143

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Wed 7/2

6:00 am-5:11 pm

2 stops10h 11m

$223

Flights are sorted by cheapest round-trip flights first.

Deals found on 4/28

Compare providers for flights from St. Louis to Dulles Intl

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from St. Louis to Dulles Intl in April.

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy1 star	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*2 stars
eDreams	Price Accuracy3 stars	Trust Score*3 stars
Priceline	Price Accuracy1 star	Trust Score*3 stars

*The Trust Score is based on feedback from users after their booking experience. It measures overall satisfaction, helping us identify issues like hidden fees, problems during the ticketing process, and the quality of customer service. This score is our best indicator of the provider's quality and reliability.

Most accurate provider: When it comes to deals on St. Louis-Washington, D.C. Dulles Intl Airport flights, users find the pricing of FlightHub to be most consistent on Cheapflights vs. FlightHub Users can find the same prices on St. Louis-Washington, D.C. Dulles Intl Airport flight deals on Cheapflights vs. FlightHub >95% of the time. Price accuracy is based on data collected from St. Louis-Washington, D.C. Dulles Intl Airport flight searches over the past month and is updated monthly.
Most trusted provider: When it comes to deals on St. Louis-Washington, D.C. Dulles Intl Airport flights, Cheapflights users trust eDreams the most. eDreams has received a user feedback score of 3 out of 3 stars (3 being the best), meaning they have been trusted the most by Cheapflights users looking for St. Louis-Washington, D.C. Dulles Intl Airport flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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

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

Airports

STL

Expect security screening at STL to take 5-10 minutes during off-peak times. Check real-time wait times online before heading to the airport.

IAD

The Washington Metro Silver Line reaches IAD in under 40 minutes, offering a cheap way to get to the city.

Our travel experts

Taryn White

Expert on STL

Ramsey Qubein

Expert on IAD

Best time to book a flight from St. Louis to Dulles Intl

Have a flexible travel schedule? Discover the best time to fly to Dulles Intl 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. Dulles Intl Airport

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

The best time to book flights from St. Louis to Washington, D.C. Dulles Intl Airport is 75 days before your desired departure date. The cost of your flight will likely increase significantly if you book two weeks in advance of your flight.

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

Currently, August is the cheapest month in which you can book a flight from St. Louis to Washington, D.C. Dulles Intl Airport (average of $309). Flying from St. Louis to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of $373). 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 IAD?

It’s optimal to fly from St. Louis to Washington, D.C. Dulles Intl Airport in the evening. By choosing this option you can save up to 78% on the cost of your flight, compared to a flight at noon.

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

The most flights from STL to IAD are scheduled on a Monday (6 on average). You will have fewer flight options on Thursday, which is when the least amount of flights are scheduled (2 on average).

Rainfall in Dulles Intl by month

In terms of precipitation, rainfall in Washington, D.C. Dulles Intl Airport 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. Dulles Intl Airport when rainfall is around 2.6 in.

Temperature in Dulles Intl by month

If weather is an important factor for your trip to Washington, D.C. Dulles Intl Airport, 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).

Reviews of airlines servicing Dulles Intl

To help decide which airline to fly from St. Louis to Washington, D.C., see what other customers have to say about Delta, United Airlines and American Airlines. In addition to providing an overall rating, users have also rated airlines in terms of entertainment options, comfort, food, crew/service, and boarding process.

Delta

8.0

Very good

7,929 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Delta

8.0

Very good

7,929 reviews

Delta

8.0

Very good

7,929 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

United Airlines

7.4

Good

8,696 reviews

Delta

8.0

Very good

7,929 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

American Airlines

7.2

Good

10,000 reviews

Delta

8.0

Very good

7,929 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Frontier

6.0

Okay

3,285 reviews

Delta

8.0

Very good

7,929 reviews

Reviews

1 / 20

10.0

Excellent

Aaron,Oct 2024

TUS - LAX

Delta has consistently been the best U.S. airline for my travels and this flight was no exception

Related info for your journey

What airport do you fly from for flights from St. Louis to Washington, D.C. Dulles Intl?
Most people fly from Lambert-St Louis (STL) if they book a flight from St. Louis to Washington, D.C. Dulles Intl. On average, Lambert-St Louis has 3 outbound flights to Washington, D.C. Dulles Intl per day from 3 airlines. Lambert-St Louis is conveniently located just 12.7 mi from St. Louis’s city center.
What are the cheapest airlines flying from St. Louis to Washington, D.C. Dulles Intl Airport round-trip?
Currently priced at $204, United Airlines will fly you from St. Louis to Washington, D.C. Dulles Intl Airport and back. In addition to United Airlines, many other airlines offer competitively priced options for your trip. Search Cheapflights for deals from Frontier and Delta - these airlines can fly you to your destination from $208 and $224, respectively. United Airlines is 46% 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. Dulles Intl Airport one-way?
To fly one-way, consider booking your trip with Delta, which is currently one of the cheapest options available, starting at $100. Frontier flights start at $110 while deals on United Airlines start at $115 one-way.
What are the most reliable airlines from St. Louis to Washington, D.C. Dulles Intl Airport?
No one likes to see their flight delayed. When booking a flight from St. Louis to Washington, D.C. Dulles Intl Airport consider choosing GoJet (82%), Avianca (82%) or Copa Airlines (82%) as they are the most reliable in getting you off to your destination on time.
What are the cheapest flights from St. Louis to Washington, D.C. Dulles Intl Airport?
On average you can expect to pay $1,212 for a flight from St. Louis to Washington, D.C. Dulles Intl Airport. The cheapest flight overall is $148 while the most popular route, (Lambert-St Louis - Washington, D.C. Dulles Intl) is currently priced at $199.
Can I find deals for flights from St. Louis to Dulles Intl that include hotel bookings?
Yes. In addition to deals on St. Louis to Dulles Intl flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from St. Louis to Dulles Intl?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from St. Louis to Dulles Intl.
Can I find deals for business class flights from St. Louis to Dulles Intl?
Yes. Cheapflights offers flight deals from St. Louis to Dulles Intl 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. Dulles Intl Airport?
Currently, August is the cheapest month in which you can book a flight from St. Louis to Washington, D.C. Dulles Intl Airport (average of $309). Flying from St. Louis to Washington, D.C. Dulles Intl Airport in June is currently the most expensive (average of $373). 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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Fairfax

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Springfield

Rockville

Fredericksburg

Gaithersburg

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Linthicum Heights

Falls Church

Laurel

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Bowie

Towson

National Harbor

Oxon Hill

Browse thousands of different options on Cheapflights for your next trip

Top 3 airlines flying from St. Louis to Dulles Intl

Airline	Cheapest	Average	Flexibility	On-time
American Airlines	Cheapest$129	Average$307	FlexibilityNo cancel fee	On-time71%
Delta	Cheapest$202	Average$266	FlexibilityNo cancel fee	On-timeN/A
United Airlines	Cheapest$211	Average$441	FlexibilityNo cancel fee	On-time69%

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$100+ Cheap flights from St. Louis (STL) to Dulles Intl (IAD)

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 5/28. Fares are subject to change and may not be available on all flights or dates of travel.

Find cheap flights from St. Louis to Dulles Intl with Cheapflights

1. Tell us where you want to go

2. Select your favorite providers

3. Compare prices and book

Cheapflights Tip: The best prices from Lambert-St Louis to Washington, D.C. Dulles Intl are usually found in January or March, booked 75 days in advance, depart on a Friday or Tuesday and return on a Wednesday

Cheap flight deals from St. Louis to Dulles Intl

Most accurate provider

Most trusted provider

Round-trip from

One-way from

Popular in

Cheapest in

Average price

Good round-trip deal

Good one-way deal

Find flight deals from St. Louis to Dulles Intl

Cheapest flights from St. Louis to Dulles IntlExplore the most affordable flight options available from St. Louis to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 29, 2025.

Explore the most affordable flight options available from St. Louis to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 29, 2025.

Cheapflights Fare Finder

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

Compare providers for flights from St. Louis to Dulles Intl

Provider information is updated monthly. Please note that these providers often have deals for this flight, but the availability may vary on a day-by-day basis on Cheapflights.

Use the table below to compare price accuracy, trust ratings, and cancellation policies for each provider offering flight deals from St. Louis to Dulles Intl in April.

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

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

Airports

STL

IAD

Our travel experts

Best time to book a flight from St. Louis to Dulles Intl

Have a flexible travel schedule? Discover the best time to fly to Dulles Intl 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. Dulles Intl Airport

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

Use this chart to determine the optimal time to book a round-trip flight from St. Louis to Dulles Intl. Price data was last updated on April 25, 2025.

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

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

Find hourly flight availability from St. Louis to Dulles Intl. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated April 29, 2025.

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

Rainfall in Dulles Intl by month

Plan your trip to Dulles Intl by taking into account the average rainfall totals by month.

Temperature in Dulles Intl by month

Plan your trip to Dulles Intl by taking into account the average temperature totals by month.

Reviews of airlines servicing Dulles Intl

Related info for your journey

Find useful and relevant information for your journey from St. Louis to Dulles Intl. 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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Cheapest flights from St. Louis to Dulles Intl
Explore the most affordable flight options available from St. Louis to Dulles Intl. Find the lowest fares from popular airlines and budget airlines, with prices last updated on April 29, 2025.