How long is the flight from Washington, D.C. Dulles Intl Airport to St. Louis?

Airlines like United Airlines and Delta fly from Washington, D.C. Dulles Intl Airport to St. Louis in about 4h 44m. The time it takes to get you to your destination can typically vary by up to 03m. The distance from Washington, D.C. Dulles Intl Airport to St. Louis is about 694 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.

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

Cheapflights users have booked flights from Washington, D.C. Dulles Intl Airport to St. Louis round-trip from $78. Other airlines that can offer you cheap pricing are Delta, from $124, and American Airlines, from $254. These flights start at 82% lower than the current average price 3 months from now.

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

The cheapest airlines for a one-way flight from Washington, D.C. Dulles Intl Airport to St. Louis are Frontier ($60), Delta ($128), and United Airlines ($141).

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

The most flights from IAD to STL are scheduled on a Monday (8 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (8 on average).

In terms of precipitation, rainfall in St. Louis ranges from 2.2 - 4.7 inches per month. May is typically the wettest month, when rainfall can reach 4.7 in. February is typically the driest time to visit St. Louis when rainfall is around 2.2 in.

If weather is an important factor for your trip to St. Louis, 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 32.0 F).

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

Looking for the cheapest flight from Washington, D.C. Dulles Intl Airport to St. Louis? While on average our users pay $730, our data indicates the cheapest price to be $207. The most popular route (Washington, D.C. Dulles Intl - Lambert-St Louis), is priced around $163.

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

Consider Avianca (73%), Copa Airlines (73%) or Brussels Airlines (63%) when booking your flight. These represent the most reliable airlines when flying from Washington, D.C. Dulles Intl Airport to St. Louis.

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

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

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

Most trusted provider : When it comes to deals on Washington, D.C. Dulles Intl Airport-St. Louis flights, Cheapflights users trust FlightHub the most. FlightHub 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 Washington, D.C. Dulles Intl Airport-St. Louis flight deals. Provider user feedback score is based on Cheapflights searches over the past month and is updated monthly.

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

If you book a flight to St. Louis from Washington, D.C. Dulles Intl, you will be flying to 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 8 flights from Washington, D.C. Dulles Intl to Lambert-St Louis per day from 4 different airlines.

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

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

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

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

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

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

$126+ Cheap Flights from Washington, D.C. Dulles Intl Airport to St. Louis

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Cheap flight deals from Dulles Intl to St. Louis

Cheapest

Best

Last-minute

One-way

Cheapest flights from Dulles Intl to St. Louis
Explore the most affordable flight options available from Dulles Intl to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 17, 2026.

Mon 10/127:50 am -

1 stop10h 50m

Mon 10/196:35 pm -

1 stop4h 46m

Deal found 9/14

$237

Sat 10/175:55 pm -

Nonstop2h 26m

Tue 10/207:01 pm -

1 stop4h 57m

Deal found 9/16

$241

Fri 11/137:40 am -

1 stop11h 00m

Sun 11/154:26 pm -

1 stop16h 55m

Deal found 9/16

$242

Wed 10/77:50 am -

1 stop6h 20m

Sat 10/104:30 pm -

1 stop16h 47m

Deal found 9/14

$245

Wed 10/147:50 am -

1 stop10h 50m

Fri 10/166:35 pm -

1 stop4h 46m

Deal found 9/15

$246

Thu 10/226:00 am -

1 stop31h 35m

Sun 10/254:30 pm -

1 stop16h 47m

Deal found 9/16

$248

Wed 10/217:50 am -

1 stop10h 50m

Mon 10/261:30 pm -

1 stop15h 50m

Deal found 9/13

$249

Sat 10/2411:12 am -

1 stop13h 01m

Sun 10/254:30 pm -

1 stop16h 47m

Deal found 9/15

$250

Wed 10/2110:57 am -

1 stop3h 56m

Wed 10/286:00 am -

1 stop4h 32m

Deal found 9/16

$251

Fri 11/137:40 am -

1 stop11h 00m

Mon 11/166:44 pm -

2 stops15h 52m

Deal found 9/13

$252

Mon 11/25:29 pm -

1 stop5h 11m

Wed 11/41:00 pm -

Nonstop2h 09m

Deal found 9/16

$253

Wed 9/306:00 am -

1 stop30h 17m

Mon 10/52:29 pm -

1 stop8h 41m

Deal found 9/14

$257

Best flights from Dulles Intl to St. Louis
Discover carefully curated flight deals from Dulles Intl to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 17, 2026.

Tue 11/108:23 am -

1 stop4h 47m

Sat 11/141:00 pm -

Nonstop2h 09m

Deal found 9/13

$265

Thu 10/86:05 am -

1 stop4h 44m

Mon 10/127:20 pm -

1 stop4h 22m

Deal found 9/15

$321

Sat 10/318:40 am -

Nonstop2h 32m

Mon 11/210:53 am -

1 stop5h 31m

Deal found 9/16

$333

Thu 10/296:05 am -

1 stop4h 44m

Sun 11/16:47 am -

1 stop3h 47m

Deal found 9/15

$341

Wed 10/148:20 am -

Nonstop2h 21m

Sat 10/175:36 pm -

1 stop4h 16m

Deal found 9/16

$352

Wed 10/146:45 am -

1 stop5h 37m

Wed 10/218:30 am -

Nonstop2h 16m

Deal found 9/12

$375

Thu 10/13:15 pm -

1 stop5h 43m

Mon 10/55:59 pm -

1 stop4h 10m

Deal found 9/14

$436

Thu 10/15:20 pm -

1 stop6h 39m

Mon 10/58:30 am -

Nonstop2h 16m

Deal found 9/14

$467

Sat 10/105:55 pm -

Nonstop2h 26m

Sun 10/118:30 am -

Nonstop2h 16m

Deal found 9/12

$467

Sat 9/2610:30 am -

1 stop4h 46m

Sat 9/265:36 pm -

1 stop4h 16m

Deal found 9/16

$519

Last-minute flights from Dulles Intl to St. Louis
Discover last-minute flight deals from Dulles Intl to St. Louis. Data last updated September 17, 2026 and is based on user searches.

Wed 10/77:50 am -

1 stop6h 20m

Sat 10/104:30 pm -

1 stop16h 47m

Deal found 9/14

$245

Mon 10/127:50 am -

1 stop10h 50m

Mon 10/196:35 pm -

1 stop4h 46m

Deal found 9/14

$237

Wed 10/147:50 am -

1 stop10h 50m

Fri 10/166:35 pm -

1 stop4h 46m

Deal found 9/15

$246

Thu 10/156:00 am -

1 stop31h 35m

Thu 10/224:30 pm -

1 stop16h 47m

Deal found 9/16

$239

Sat 10/175:55 pm -

Nonstop2h 26m

Tue 10/207:01 pm -

1 stop4h 57m

Deal found 9/16

$241

Wed 10/217:50 am -

1 stop10h 50m

Mon 10/261:30 pm -

1 stop15h 50m

Deal found 9/13

$249

Wed 10/2110:57 am -

1 stop3h 56m

Wed 10/286:00 am -

1 stop4h 32m

Deal found 9/16

$251

Thu 10/226:00 am -

1 stop31h 35m

Sun 10/254:30 pm -

1 stop16h 47m

Deal found 9/16

$248

Sat 10/2411:12 am -

1 stop13h 01m

Thu 10/294:26 pm -

1 stop16h 55m

Deal found 9/16

$242

Sat 10/2411:12 am -

1 stop13h 01m

Sun 10/254:30 pm -

1 stop16h 47m

Deal found 9/15

$250

Sat 10/246:45 am -

1 stop5h 48m

Thu 10/291:00 pm -

Nonstop2h 09m

Deal found 9/16

$253

One-way flights from Dulles Intl to St. Louis
Search for one-way flight options from Dulles Intl to St. Louis. Find affordable one-way fares based on user searches. Data last updated September 17, 2026.

Sat 10/105:01 am -

1 stop4h 36m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 9/15

$126

Sun 10/2511:12 am -

2 stops31h 28m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 9/15

$128

Sat 10/36:00 am -

1 stop30h 17m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 9/12

$134

Mon 11/233:37 pm -

1 stop4h 46m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 9/13

$138

Fri 11/67:40 am -

1 stop11h 00m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 9/13

$141

Sat 11/219:35 pm -

1 stop27h 24m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 9/15

$145

Sat 10/105:55 pm -

Nonstop2h 26m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 9/15

$147

Thu 10/89:06 pm -

1 stop21h 34m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 9/12

$148

Tue 11/249:35 pm -

1 stop27h 24m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 9/16

$149

Mon 10/57:17 pm -

1 stop5h 25m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 9/15

$150

Mon 9/2811:12 am -

1 stop6h 22m

Wed 12/3112:00 am -

Nonstop0h 00m

Deal found 9/14

$160

Find flight deals from Dulles Intl to St. Louis

Most accurate provider	FlightHub 3 stars
Most trusted provider	FlightHub 3 stars
Round-trip from	$237 (Super.com)
One-way from	$126 (American Airlines)
Popular in	June
Cheapest in	October
Average price	$529
Good round-trip deal	$529 or less
Good one-way deal	$242 or less

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

Search Deals

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

Search Deals

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

Search Deals

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

Search Deals

Highest demand for flights based on searches. 16% potential increase in price ($90 potential increase over avg. RT price).

Search Deals

Cheapest flight prices on average. 3% potential price decrease ($17 potential savings vs. average RT price).

Search Deals

Average for round-trip flights in September 2026

Search Deals

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

Search Deals

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

Search Deals

Cheapflights Fare Finder

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

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

Washington, D.C.St. Louis

IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis

IADSTL

Washington, D.C. Dulles Intl

Mon 11/23

8:40 am-10:12 am

Nonstop2h 32m

Lambert-St Louis

Wed 12/31

12:00 am-1:00 am

Nonstop0h 00m

$128

Washington, D.C.St. Louis

IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis

IADSTL

Washington, D.C. Dulles Intl

Sat 11/21

9:35 pm-11:59 pm

1 stop27h 24m

Lambert-St Louis

Wed 12/31

12:00 am-1:00 am

Nonstop0h 00m

$145

Washington, D.C.St. Louis

IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis

IADSTL

Washington, D.C. Dulles Intl

Sun 11/1

11:16 am-11:16 pm

1 stop13h 00m

Lambert-St Louis

Wed 12/31

12:00 am-1:00 am

Nonstop0h 00m

$180

Washington, D.C.St. Louis

IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis

IADSTL

Washington, D.C. Dulles Intl

Tue 9/22

6:00 am-11:32 am

1 stop30h 32m

Lambert-St Louis

Wed 12/31

12:00 am-1:00 am

Nonstop0h 00m

$186

Washington, D.C.St. Louis

IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis

IADSTL

Washington, D.C. Dulles Intl

Sat 11/21

5:55 pm-7:30 pm

Nonstop2h 35m

Lambert-St Louis

Wed 12/31

12:00 am-1:00 am

Nonstop0h 00m

$223

Washington, D.C.St. Louis

IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis

IADSTL

Washington, D.C. Dulles Intl

Tue 9/29

5:55 pm-7:21 pm

Nonstop2h 26m

Lambert-St Louis

Wed 12/31

12:00 am-1:00 am

Nonstop0h 00m

$253

Washington, D.C.St. Louis

IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis

IADSTL

Washington, D.C. Dulles Intl

Tue 11/10

8:23 am-12:10 pm

1 stop4h 47m

Lambert-St Louis

Sat 11/14

1:00 pm-4:09 pm

Nonstop2h 09m

$265

Quickest round-trip

Washington, D.C.St. Louis

IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis

IADSTL

Washington, D.C. Dulles Intl

Tue 9/22

8:25 am-9:39 am

Nonstop2h 14m

Lambert-St Louis

Wed 12/31

12:00 am-1:00 am

Nonstop0h 00m

$282

Washington, D.C.St. Louis

IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis

IADSTL

Washington, D.C. Dulles Intl

Thu 9/24

6:00 am-10:55 am

1 stop5h 55m

Lambert-St Louis

Wed 12/31

12:00 am-1:00 am

Nonstop0h 00m

$292

Washington, D.C.St. Louis

IAD Washington, D.C. Dulles Intl - STL Lambert-St Louis

IADSTL

Washington, D.C. Dulles Intl

Sun 9/20

6:00 am-10:55 am

1 stop5h 55m

Lambert-St Louis

Wed 12/31

12:00 am-1:00 am

Nonstop0h 00m

$292

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/13

Showing 1-10 of 19 resultsSorted by cheapest first

Compare providers for flights from Dulles Intl to St. Louis

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

Provider	Price Accuracy	Trust Score*
Expedia	Price Accuracy1 star	Trust Score*3 stars
FlightHub	Price Accuracy3 stars	Trust Score*3 stars
JustAirTicket	Price Accuracy-	Trust Score*1 star

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

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

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Dulles Intl with our price prediction graph.

IAD-STL

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

Prices

Airlines

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

Currently, October is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to St. Louis (average of $318). Flying from Washington, D.C. Dulles Intl Airport to St. Louis in June is currently the most expensive (average of $636). 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 IAD to STL?

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Washington, D.C. Dulles Intl Airport to St. Louis as you normally would.

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

Airfare is below average for this route at the moment.

Washington, D.C. Dulles Intl Airport to St. Louis flights typically cost between $306 and $578 in October.
The cheapest round-trip price found within the last 5 days was $237 on Frontier (Oct 12-Oct 19).

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

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

Our travel experts

Taryn White

Expert on STL

Taryn White is a freelance travel writer, digital creator, and travel advisor who has visited nearly 100 countries and all 50 states. She’s familiar with many airports and enjoys beach hopping, boutique hotels, spa experiences, and exploring local culture. Her work has appeared in Travel + Leisure, Condé Nast Traveler, National Geographic, Smithsonian Magazine, AFAR, and more.

Ramsey Qubein

Expert on IAD

An avid traveler and aviation expert who has visited 173 countries, all 50 states and seven continents, Ramsey Qubein flies nearly 400,000 miles a year. As a North Carolina-based freelance journalist for publications including Conde Nast Traveler, Forbes, USA Today and Bloomberg among others, he explores the latest trends in aviation, hospitality, cruises and business.

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

Delta

7.8

Good

8,579 reviews

Reviews

1 / 20

4.0

Okay

Jennifer,Sep 2026

ORD - LGA

The flight crew was 30 minutes late to an am flight and then that caused a delay

Delta

7.8

Good

8,579 reviews

Delta

7.8

Good

8,579 reviews

Reviews

1 / 20

4.0

Okay

Jennifer,Sep 2026

ORD - LGA

The flight crew was 30 minutes late to an am flight and then that caused a delay

United Airlines

7.4

Good

10,214 reviews

Delta

7.8

Good

8,579 reviews

Reviews

1 / 20

4.0

Okay

Jennifer,Sep 2026

ORD - LGA

The flight crew was 30 minutes late to an am flight and then that caused a delay

American Airlines

7.1

Good

12,076 reviews

Delta

7.8

Good

8,579 reviews

Reviews

1 / 20

4.0

Okay

Jennifer,Sep 2026

ORD - LGA

The flight crew was 30 minutes late to an am flight and then that caused a delay

Frontier

5.6

Fair

2,600 reviews

Delta

7.8

Good

8,579 reviews

Reviews

1 / 20

4.0

Okay

Jennifer,Sep 2026

ORD - LGA

The flight crew was 30 minutes late to an am flight and then that caused a delay

Related info for your journey

What airport do you fly into for flights to St. Louis from Washington, D.C. Dulles Intl?
If you book a flight to St. Louis from Washington, D.C. Dulles Intl, you will be flying to 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 8 flights from Washington, D.C. Dulles Intl to Lambert-St Louis per day from 4 different airlines.
How long is the flight from Washington, D.C. Dulles Intl Airport to St. Louis?
Airlines like United Airlines and Delta fly from Washington, D.C. Dulles Intl Airport to St. Louis in about 4h 44m. The time it takes to get you to your destination can typically vary by up to 03m. The distance from Washington, D.C. Dulles Intl Airport to St. Louis is about 694 mi. When browsing for deals, the options you’ll see will be for both nonstop flights and flights with stops.
What are the cheapest airlines flying from Washington, D.C. Dulles Intl Airport to St. Louis round-trip?
Cheapflights users have booked flights from Washington, D.C. Dulles Intl Airport to St. Louis round-trip from $78. Other airlines that can offer you cheap pricing are Delta, from $124, and American Airlines, from $254. These flights start at 82% lower than the current average price 3 months from now.
What are the cheapest airlines to fly from Washington, D.C. Dulles Intl Airport to St. Louis one-way?
The cheapest airlines for a one-way flight from Washington, D.C. Dulles Intl Airport to St. Louis are Frontier ($60), Delta ($128), and United Airlines ($141).
What are the most reliable airlines from Washington, D.C. Dulles Intl Airport to St. Louis?
Consider Avianca (73%), Copa Airlines (73%) or Brussels Airlines (63%) when booking your flight. These represent the most reliable airlines when flying from Washington, D.C. Dulles Intl Airport to St. Louis.
What are the cheapest flights from Washington, D.C. Dulles Intl Airport to St. Louis?
Looking for the cheapest flight from Washington, D.C. Dulles Intl Airport to St. Louis? While on average our users pay $730, our data indicates the cheapest price to be $207. The most popular route (Washington, D.C. Dulles Intl - Lambert-St Louis), is priced around $163.
Can I find deals for flights from Dulles Intl to St. Louis that include hotel bookings?
Yes. In addition to deals on Dulles Intl to St. Louis flights, Cheapflights offers vacation packages that include both flights and hotel.
How can I find direct flights from Dulles Intl to St. Louis?
After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Dulles Intl to St. Louis.
Can I find deals for business class flights from Dulles Intl to St. Louis?
Yes. Cheapflights offers flight deals from Dulles Intl to St. Louis 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 Washington, D.C. Dulles Intl Airport to St. Louis?
Currently, October is the cheapest month in which you can book a flight from Washington, D.C. Dulles Intl Airport to St. Louis (average of $318). Flying from Washington, D.C. Dulles Intl Airport to St. Louis in June is currently the most expensive (average of $636). 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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Eureka

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Alternative routes

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Other flight options

Other flights from Dulles Intl

Popular flights

St. Louis flight routes

Top 4 airlines flying from Dulles Intl to St. Louis

Airline	Cheapest	Average	Flexibility	On-time
Frontier	Cheapest$78	Average$229	FlexibilityNo cancel fee	On-time62%
Delta	Cheapest$124	Average$318	FlexibilityNo cancel fee	On-timeN/A
American Airlines	Cheapest$254	Average$364	FlexibilityNo cancel fee	On-time71%
United Airlines	Cheapest$278	Average$567	FlexibilityNo cancel fee	On-time69%

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$126+ Cheap flights from Dulles Intl (IAD) to St. Louis (STL)

This is the cheapest round-trip flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/10. Fares are subject to change and may not be available on all flights or dates of travel.

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Cheap flight deals from Dulles Intl to St. Louis

Cheapest flights from Dulles Intl to St. LouisExplore the most affordable flight options available from Dulles Intl to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 17, 2026.

Explore the most affordable flight options available from Dulles Intl to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 17, 2026.

Best flights from Dulles Intl to St. LouisDiscover carefully curated flight deals from Dulles Intl to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 17, 2026.

Discover carefully curated flight deals from Dulles Intl to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 17, 2026.

Last-minute flights from Dulles Intl to St. LouisDiscover last-minute flight deals from Dulles Intl to St. Louis. Data last updated September 17, 2026 and is based on user searches.

Discover last-minute flight deals from Dulles Intl to St. Louis. Data last updated September 17, 2026 and is based on user searches.

One-way flights from Dulles Intl to St. LouisSearch for one-way flight options from Dulles Intl to St. Louis. Find affordable one-way fares based on user searches. Data last updated September 17, 2026.

Search for one-way flight options from Dulles Intl to St. Louis. Find affordable one-way fares based on user searches. Data last updated September 17, 2026.

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

Compare providers for flights from Dulles Intl to St. Louis

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 Dulles Intl to St. Louis in September.

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

Have a flexible travel schedule? Discover the best time to fly to St. Louis from Dulles Intl with our price prediction graph.

Cheapflights Insights

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

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

Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Washington, D.C. Dulles Intl Airport to St. Louis as you normally would.

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

Airfare is below average for this route at the moment.

Washington, D.C. Dulles Intl Airport to St. Louis flights typically cost between $306 and $578 in October.The cheapest round-trip price found within the last 5 days was $237 on Frontier (Oct 12-Oct 19).

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

The most flights from IAD to STL are scheduled on a Monday (8 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (8 on average).

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

AI-powered summary based on content written by travel experts. AI can make mistakes.

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

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Reviews of airlines servicing St. Louis

Get a feel of what it's like to fly with Delta,United Airlines, andAmerican Airlines from Washington, D.C. Dulles Intl Airport to St. Louis 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

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

How long is the flight from Washington, D.C. Dulles Intl Airport to St. Louis?

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

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

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

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

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

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

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

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

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Alternative routes for Dulles Intl to St. Louis

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Dulles Intl and St. Louis flights

Browse other Dulles Intl and St. Louis flight options. Last updated on September 17, 2026.

Other flights from Dulles Intl

Browse through other flights departing from Dulles Intl. Flights are based on user searches made on Cheapflights and were last updated on September 17, 2026.

Popular flight searches

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Other flights to St. Louis

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Top 4 airlines flying from Dulles Intl to St. Louis

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Cheapest flights from Dulles Intl to St. Louis
Explore the most affordable flight options available from Dulles Intl to St. Louis. Find the lowest fares from popular airlines and budget airlines, with prices last updated on September 17, 2026.

Best flights from Dulles Intl to St. Louis
Discover carefully curated flight deals from Dulles Intl to St. Louis that have cost, travel time, and layovers in mind to ensure you get the best travel experience. Data last updated September 17, 2026.

Last-minute flights from Dulles Intl to St. Louis
Discover last-minute flight deals from Dulles Intl to St. Louis. Data last updated September 17, 2026 and is based on user searches.

One-way flights from Dulles Intl to St. Louis
Search for one-way flight options from Dulles Intl to St. Louis. Find affordable one-way fares based on user searches. Data last updated September 17, 2026.

Washington, D.C. Dulles Intl Airport to St. Louis flights typically cost between $306 and $578 in October.
The cheapest round-trip price found within the last 5 days was $237 on Frontier (Oct 12-Oct 19).