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

4 flights are operational daily from St. Louis to Washington, D.C. Dulles Intl Airport as of March 2026. The most popular departure time for this route is 12:00PM, with 57% of flights per day taking off in the afternoon.

What airlines fly to Washington, D.C. Dulles Intl Airport?

United Airlines, Delta and American Airlines are the top three most popular airlines that fly to Washington, D.C. Dulles Intl Airport from St. Louis according to our data. United Airlines is the first choice among our users, with 56% of people opting to fly with this airline when traveling to Washington, D.C. Dulles Intl Airport. Keep in mind that there are 4 different airlines that fly to Washington, D.C. Dulles Intl Airport on a routine basis, so you have a few additional options to choose from.

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

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

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

Prices for flights from Lambert-St Louis Airport to Washington, D.C. Dulles Intl Airport are refreshed on a daily basis.

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

The number of operators available for flights from Lambert-St Louis Airport to Washington, D.C. Dulles Intl Airport is 4 as of March 2026.

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

Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Lambert-St Louis Airport to Washington, D.C. Dulles Intl Airport.

What documentation or ID do you need to fly to Washington, D.C. Dulles Intl Airport?

The necessary travel and health documents for your Washington, D.C. Dulles Intl Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.

$70 Cheap Flights from St. Louis to Washington, D.C. Dulles Intl Airport in 2026

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

Prices are currently low for flights on this route. Typical prices usually range from $456 to $278. The lowest price recently found on this route was $237.

1 adult

0 bags

Discover deals from 900+ travel sites with momondo.

Save money when you book flights with momondo

Big names and deals

Search 100s of travel sites to compare prices.

Filter for what you want

Free Wi-Fi? Stopover? Instantly customize your results.

Trusted and free

We’re completely free to use - no hidden charges or fees.

Price Alerts

Not ready to book? to track prices.

Search flight deals

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 - 9:54 am

STL

IAD

12h 31m

1 stop

6:19 pm - 11:19 pm

IAD

STL

30h 00m

2 stops

$237Frontier

Fri, Apr 17 - Mon, Apr 20

5:27 pm - 10:12 am

STL

IAD

15h 45m

1 stop

11:12 am - 12:21 am

IAD

STL

14h 09m

2 stops

$239Frontier

Sat, May 16 - Mon, May 18

8:08 pm - 10:12 am

STL

IAD

13h 04m

2 stops

7:45 am - 5:33 pm

IAD

STL

10h 48m

1 stop

$241Frontier

Fri, May 29 - Thu, Jun 4

9:10 am - 4:03 pm

STL

IAD

5h 53m

1 stop

5:26 pm - 9:13 pm

IAD

STL

4h 47m

1 stop

$242United Airlines

Tue, Apr 21 - Tue, Apr 28

8:08 pm - 10:12 am

STL

IAD

13h 04m

2 stops

5:26 pm - 8:55 am

IAD

STL

16h 29m

1 stop

$243Frontier

Fri, May 8 - Sun, May 10

8:06 pm - 11:39 am

STL

IAD

14h 33m

2 stops

1:26 pm - 11:19 pm

IAD

STL

10h 53m

1 stop

$246Frontier

Thu, Apr 16 - Sun, Apr 19

4:59 pm - 9:54 am

STL

IAD

15h 55m

2 stops

1:26 pm - 11:19 pm

IAD

STL

10h 53m

1 stop

$248Frontier

Fri, Apr 17 - Sun, Apr 19

8:08 pm - 10:12 am

STL

IAD

13h 04m

2 stops

6:17 pm - 8:55 am

IAD

STL

15h 38m

1 stop

$250Frontier

Fri, May 8 - Fri, May 15

9:16 am - 4:03 pm

STL

IAD

5h 47m

1 stop

9:00 am - 10:31 am

IAD

STL

2h 31mnonstop

$253United Airlines

Sat, Apr 18 - Sat, Apr 25

4:59 pm - 12:46 pm

STL

IAD

18h 47m

1 stop

1:26 pm - 11:19 pm

IAD

STL

10h 53m

1 stop

$257Frontier

Thu, Apr 16 - Sun, Apr 19

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

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

United Airlines

Apr 21

STL9:10 amLambert-St Louis

5h 53m

1 stop

IAD4:03 pmWashington, D.C. Dulles Intl

Apr 28

IAD5:26 pmWashington, D.C. Dulles Intl

4h 47m

1 stop

STL9:13 pmLambert-St Louis

$242

United Airlines

Apr 18

STL9:16 amLambert-St Louis

5h 47m

1 stop

IAD4:03 pmWashington, D.C. Dulles Intl

Apr 25

IAD9:00 amWashington, D.C. Dulles Intl

2h 31m

STL10:31 amLambert-St Louis

$253

United Airlines

May 30

STL9:23 amLambert-St Louis

6h 03m

1 stop

IAD4:26 pmWashington, D.C. Dulles Intl

Jun 4

IAD9:00 amWashington, D.C. Dulles Intl

2h 27m

STL10:27 amLambert-St Louis

$284

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

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

Delta

Apr 18

STL1:03 pmLambert-St Louis

5h 53m

1 stop

IAD7:56 pmWashington, D.C. Dulles Intl

Apr 20

IAD7:19 pmWashington, D.C. Dulles Intl

5h 17m

1 stop

STL11:36 pmLambert-St Louis

$263

Delta

Apr 14

STL1:02 pmLambert-St Louis

6h 50m

1 stop

IAD8:52 pmWashington, D.C. Dulles Intl

Apr 22

IAD3:00 pmWashington, D.C. Dulles Intl

7h 19m

1 stop

STL9:19 pmLambert-St Louis

$273

Delta

Jun 10

STL1:39 pmLambert-St Louis

6h 25m

1 stop

IAD9:04 pmWashington, D.C. Dulles Intl

Jun 15

IAD7:39 pmWashington, D.C. Dulles Intl

5h 17m

1 stop

STL11:56 pmLambert-St Louis

$278

momondo 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

Cheapest round-trip

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Fri 4/17

8:23 pm-9:54 am

1 stop12h 31m

Washington, D.C. Dulles Intl

Mon 4/20

6:19 pm-11:19 pm

2 stops30h 00m

$237

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Sat 5/16

5:27 pm-10:12 am

1 stop15h 45m

Washington, D.C. Dulles Intl

Mon 5/18

11:12 am-12:21 am

2 stops14h 09m

$239

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Fri 5/29

8:08 pm-10:12 am

2 stops13h 04m

Washington, D.C. Dulles Intl

Thu 6/4

7:45 am-5:33 pm

1 stop10h 48m

$241

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Tue 4/21

9:10 am-4:03 pm

1 stop5h 53m

Washington, D.C. Dulles Intl

Tue 4/28

5:26 pm-9:13 pm

1 stop4h 47m

$242

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Fri 5/8

8:08 pm-10:12 am

2 stops13h 04m

Washington, D.C. Dulles Intl

Sun 5/10

5:26 pm-8:55 am

1 stop16h 29m

$243

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Thu 4/16

8:06 pm-11:39 am

2 stops14h 33m

Washington, D.C. Dulles Intl

Sun 4/19

1:26 pm-11:19 pm

1 stop10h 53m

$246

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Fri 4/17

4:59 pm-9:54 am

2 stops15h 55m

Washington, D.C. Dulles Intl

Sun 4/19

1:26 pm-11:19 pm

1 stop10h 53m

$248

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Fri 5/8

8:08 pm-10:12 am

2 stops13h 04m

Washington, D.C. Dulles Intl

Fri 5/15

6:17 pm-8:55 am

1 stop15h 38m

$250

Quickest round-trip

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Sat 4/18

9:16 am-4:03 pm

1 stop5h 47m

Washington, D.C. Dulles Intl

Sat 4/25

9:00 am-10:31 am

Nonstop2h 31m

$253

St. LouisWashington, D.C.

STL - IAD

STLIAD

Lambert-St Louis

Thu 4/16

4:59 pm-12:46 pm

1 stop18h 47m

Washington, D.C. Dulles Intl

Sun 4/19

1:26 pm-11:19 pm

1 stop10h 53m

$257

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. Dulles Intl Airport

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. Dulles Intl Airport?

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

In general, February is the cheapest month to fly from St. Louis to Washington, D.C. Dulles Intl Airport. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $170. If you aren’t able to travel to Washington, D.C. Dulles Intl Airport during the month of February, then flying in September is also cheap. Prices for this month can be found on momondo for an average of $315.

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

Our data shows that Friday is the least expensive day to fly to Washington, D.C. Dulles Intl Airport. Tickets to fly out on this day can be as low as $823. When flying out on a Thursday, the most expensive travel day of the week, you can expect to see flight prices from St. Louis to Washington, D.C. Dulles Intl Airport for around $1,141.

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

Flying to Washington, D.C. Dulles Intl Airport from St. Louis in the morning is the least expensive time of day to depart. momondo users have found prices as low as $849 when looking at flights departing in the morning. If you have a flexible travel schedule, then try to avoid flying at noon when prices are $1,124 on average. Flights to Washington, D.C. Dulles Intl Airport from St. Louis at noon are generally more expensive because this time of day is more convenient for travelers’ schedules.

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

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

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

You are more likely to see cheaper flights to Washington, D.C. Dulles Intl Airport from St. Louis when booking weeks ahead of your departure date. In general, you can expect to find flights to Washington, D.C. Dulles Intl Airport for around $377 when searching weeks out. However, flight prices might be lower outside of this timeframe. For example, people recently found flights to Washington, D.C. Dulles Intl Airport from St. Louis for as low as $233 on momondo.

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

There are 4 cabin classes available to choose from on Lambert-St Louis to Washington, D.C. Dulles Intl 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. Dulles Intl Airport flights?

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

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

As of March 2026, prices for St. Louis to Washington, D.C. Dulles Intl Airport flights are approximately 39% more expensive when compared to flights at the same time last year.

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

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

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

Best Price Found	$483
Fastest flight time	2h 10m
Direct flights	Every day

The best one-way flight to Washington, D.C. Dulles Intl Airport from St. Louis in the past 72 hours is $483. The best round-trip flight deal from St. Louis to Washington, D.C. Dulles Intl Airport found on momondo in the last 72 hours is $455.

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

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

Search flight deals

How far is Lambert-St Louis to Washington, D.C. Dulles Intl by plane?
The straight-line distance from Lambert-St Louis to Washington, D.C. Dulles Intl is 685.9 mi. Flights usually cover this in 2h 10m, depending on flying conditions and air traffic around both airports.
When did momondo last update prices for flights from Lambert-St Louis Airport to Washington, D.C. Dulles Intl Airport?
Prices for flights from Lambert-St Louis Airport to Washington, D.C. Dulles Intl Airport are refreshed on a daily basis.
How many operators does momondo search for flights from Lambert-St Louis Airport to Washington, D.C. Dulles Intl Airport?
The number of operators available for flights from Lambert-St Louis Airport to Washington, D.C. Dulles Intl Airport is 4 as of March 2026.
How old do you have to be to fly from Lambert-St Louis Airport to Washington, D.C. Dulles Intl Airport?
Although the minimum age for a child to fly alone is five, airlines that offer an unaccompanied minor (UMNR) service may have their own age limits, which could be impacted by factors such as flight length, timing, and layovers. It is recommended that you verify with the airline you are booking with for travel from Lambert-St Louis Airport to Washington, D.C. Dulles Intl Airport.
What documentation or ID do you need to fly to Washington, D.C. Dulles Intl Airport?
The necessary travel and health documents for your Washington, D.C. Dulles Intl Airport trip may vary depending on your travel plans and individual circumstances. Generally, you should have various documents, such as a national ID card or driver's license and a passport that is valid for six months beyond your scheduled arrival date. We recommend seeking advice from your airline or a trusted third party, such as IATA.
What is the most popular plane model from St. Louis to Washington, D.C. Dulles Intl Airport?
Based on momondo bookings for flights between St. Louis and Washington, D.C. Dulles Intl Airport, the leading plane model is Canadair (Bombardier) Regional Jet CRJ-550, making up 39.47% of the total bookings. Other popular models include Boeing 737 MAX 8 with 10.53%, Canadair (Bombardier) Regional Jet 900 with 9.21%, and Airbus A330-300 with 7.89%.
What is the most popular airline from St. Louis to Washington, D.C. Dulles Intl Airport?
Based on momondo bookings for this flight route, the most popular airline on flight routes from St. Louis to Washington, D.C. Dulles Intl Airport is United Airlines (56% of total bookings). The next most popular airlines are Delta (27%), American Airlines (9%), and Frontier (8%).

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

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

Airline	Rating	Free Cancellation	Price
Delta	PriceFrom $99	Free Cancellation	Rating 7.9 8,332 reviews	Search Delta flights
Frontier	PriceFrom $113	Free Cancellation	Rating 5.7 3,015 reviews	Search Frontier flights
American Airlines	PriceFrom $257	Free Cancellation	Rating 7.1 11,496 reviews	Search American Airlines flights
United Airlines	PriceFrom $264	Free Cancellation	Rating 7.4 9,486 reviews	Search United Airlines flights

United Airlines Flights From St. Louis to Washington, D.C. Dulles Intl Airport
United Airlines flight deals from St. Louis to Washington, D.C. Dulles Intl Airport start from $264 round-trip. Over the 8 United Airlines flights for this route in a normal week, average airfare is usually $453 round-trip - but some users have found much cheaper deals with momondo.

Alexandria

National Harbor

Gettysburg

Arlington

Winchester

Waldorf

Woodbridge

Laurel

Colonial Beach

Gaithersburg

Towson

Silver Spring

Fredericksburg

Rockville

Tysons

Manassas

Sterling

Linthicum Heights

Springfield

Bethesda

Why use momondo?

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

We help find the flight that best suits your needs, momondo compares prices from hundreds of airlines and travel agents and helps you filter them to find the best flight from St. Louis to Washington, D.C. for you.

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

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

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

momondo offers useful filters to help you find the right flight. Choose specific flight times, airports or even what payment method you prefer. We have numerous options to help you book your ideal flight from St. Louis to Washington, D.C..

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

Yes. momondo can track prices for St. Louis to Washington, D.C. flights and alert you when they change. Perform a search to set up the price alert. All that is required is a valid email address.

An easier way to manage your Washington, D.C. Dulles Intl Airport trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Start using Trips

Find my bookings

Get notified when prices go down

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

1 adult

Sat 4/25

Sat 5/2

Email me momondo's favorite deals

By creating a price alert you accept our terms of use and privacy policy.

Find better results for your trip to Washington, D.C.

Popular cities

Other flights from St. Louis

Other flights to Washington, D.C.

Airlines

Cabin classes

Complete your trip

Feeling lucky

Popular cities in the United States

Flights to New York John F Kennedy Intl Airportfrom $91

Flights to Newark Airportfrom $68

Flights to New York LaGuardia Airportfrom $69

Flights to Chicago O'Hare Intl Airportfrom $72

Flights to Dallas/Fort Worth Airportfrom $54

Flights to Washington, D.C. Reagan-National Airportfrom $127

Flights to Orlando Airportfrom $46

Flights to Chicago Midway Airportfrom $70

Flights to Dallas Love Field Airport

Flights to Chicago Greater Rockford Airport

Cheap flights from St. Louis to Washington, D.C. from $70

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 5/6. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.

Big names and deals

Big names and deals

Filter for what you want

Filter for what you want

Trusted and free

Trusted and free

Price Alerts

Price Alerts

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

Cheap round-trip flights

Cheap one-way flights

Cheap last minute flights

Cheap direct flights

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

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

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

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

momondo 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.

See travel insights to Washington, D.C. from

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

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

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

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

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

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

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

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

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

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

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

What airlines fly to Washington, D.C. Dulles Intl Airport?

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

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

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

Cheap St. Louis to Washington, D.C. Dulles Intl Airport (STL to IAD) flight deals and tips

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

Best Price Found

Fastest flight time

Direct flights

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

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

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

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

Why use momondo?

An easier way to manage your Washington, D.C. Dulles Intl Airport trip

We make it super easy to schedule, organize and travel with friends or family. Trips is free — and available to use no matter where you book.

Get notified when prices go down

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

Find better results for your trip to Washington, D.C.

Popular cities in the United States

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

St. Louis flight routes

According to popular flight searches on momondo this year

Washington, D.C. Dulles Intl Airport flight routes

According to popular flight searches on momondo this year

Fly your favorite airline to Washington, D.C.

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

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

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

Complete your trip to Washington, D.C.

Explore popular destinations other users love

According to popular flight searches on momondo this year