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St. Louis

$88+ Cheap flights from Dulles Intl (IAD) to St. Louis (STL)

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 5/19. Fares are subject to change and may not be available on all flights or dates of travel.
IAD — STL
Apr 16 — Apr 231
Thu 4/16
Thu 4/23
1 adult, Economy
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Find cheap flights from Dulles Intl to St. Louis with Cheapflights

1. Tell us where you want to go

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Cheap flight deals from Dulles Intl to St. Louis

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 March 17, 2026.

This American Airlines deal was found by Cheapflights users on 3/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure American Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/89:19 am
IAD
-
STL
1 stop5h 03m
American Airlines
Sat 4/116:53 pm
STL
-
IAD
1 stop4h 06m
American Airlines
Deal found 3/12$274
This United Airlines deal was found by Cheapflights users on 3/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/98:20 am
IAD
-
STL
1 stop5h 02m
United Airlines
Sat 4/118:30 am
STL
-
IAD
Nonstop2h 13m
United Airlines
Deal found 3/12$275
This CheapOair deal was found by Cheapflights users on 3/12. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/241:08 pm
IAD
-
STL
1 stop11h 11m
Frontier
Sun 4/264:59 pm
STL
-
IAD
1 stop13h 33m
Frontier
Deal found 3/12$276
This Kiwi.com deal was found by Cheapflights users on 3/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/166:10 am
IAD
-
STL
1 stop5h 20m
Frontier
Tue 4/214:59 pm
STL
-
IAD
2 stops30h 37m
Frontier
Deal found 3/14$277
This Booking.com deal was found by Cheapflights users on 3/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/26:39 pm
IAD
-
STL
1 stop13h 49m
Frontier
Tue 4/74:59 pm
STL
-
IAD
1 stop16h 12m
Frontier
Deal found 3/13$278
This Kiwi.com deal was found by Cheapflights users on 3/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/206:19 pm
IAD
-
STL
2 stops30h 00m
Frontier
Sat 4/258:23 pm
STL
-
IAD
1 stop11h 33m
Frontier
Deal found 3/16$279
This Expedia deal was found by Cheapflights users on 3/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/13:08 pm
IAD
-
STL
1 stop9h 11m
Frontier
Sun 5/34:59 pm
STL
-
IAD
1 stop13h 28m
Frontier
Deal found 3/15$280
This CheapOair deal was found by Cheapflights users on 3/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 4/171:31 pm
IAD
-
STL
1 stop10h 48m
Frontier
Sun 4/194:59 pm
STL
-
IAD
1 stop13h 28m
Frontier
Deal found 3/17$281
This Booking.com deal was found by Cheapflights users on 3/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Booking.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/68:30 pm
IAD
-
STL
1 stop27h 55m
Frontier
Wed 4/84:59 pm
STL
-
IAD
1 stop17h 34m
Frontier
Deal found 3/14$283
This Kiwi.com deal was found by Cheapflights users on 3/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 4/239:41 am
IAD
-
STL
2 stops14h 38m
Multiple Airlines
Fri 4/248:23 pm
STL
-
IAD
1 stop12h 31m
Multiple Airlines
Deal found 3/15$284
This Delta deal was found by Cheapflights users on 3/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/87:18 am
IAD
-
STL
1 stop4h 51m
Delta
Sat 4/116:32 am
STL
-
IAD
1 stop4h 00m
Delta
Deal found 3/16$285
This Kiwi.com deal was found by Cheapflights users on 3/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 4/227:15 am
IAD
-
STL
2 stops17h 04m
Frontier
Thu 4/3011:21 am
STL
-
IAD
1 stop6h 21m
Frontier
Deal found 3/15$286

Find flight deals from Dulles Intl to St. Louis

Discover tips and strategies to find the most affordable flight options for your journey from Dulles Intl (IAD) to St. Louis (STL). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated March 17, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$274
(American Airlines)

One-way from

$88
(Trip.com)

Popular in

March

Cheapest in

August

Average price

$615

Good round-trip deal

$371 or less

Good one-way deal

$141 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. 13% potential increase in price ($60 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 5% potential price decrease ($21 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 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

 
Customize your flight search to find flights from Dulles Intl to St. Louis that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated March 17, 2026.
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 - STL

IADSTL

Washington, D.C. Dulles Intl

Thu 4/9

8:20 am-12:22 pm

1 stop5h 02m

Lambert-St Louis

Sat 4/11

11:15 am-5:28 pm

1 stop5h 13m

$285

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Wed 4/22

5:41 pm-11:57 pm

1 stop7h 16m

Lambert-St Louis

Sat 4/25

8:30 am-11:43 am

Nonstop2h 13m

$310

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Thu 4/23

9:00 am-10:28 am

Nonstop2h 28m

Lambert-St Louis

Tue 4/28

9:10 am-4:03 pm

1 stop5h 53m

$320

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Fri 4/17

5:55 pm-11:50 pm

1 stop6h 55m

Lambert-St Louis

Mon 4/20

3:00 pm-12:20 am

1 stop8h 20m

$321

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Fri 5/15

5:55 am-3:50 pm

1 stop10h 55m

Lambert-St Louis

Sat 5/16

6:10 am-4:25 pm

2 stops9h 15m

$389

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Thu 5/28

5:55 pm-11:50 pm

1 stop6h 55m

Lambert-St Louis

Sun 5/31

6:15 am-5:25 pm

2 stops10h 10m

$395

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Fri 5/22

7:38 pm-11:59 pm

1 stop5h 21m

Lambert-St Louis

Sun 5/24

6:00 am-11:50 am

1 stop4h 50m

$399

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Thu 6/11

6:10 am-12:11 pm

1 stop7h 01m

Lambert-St Louis

Sun 6/14

8:35 am-11:47 am

Nonstop2h 12m

$406

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Fri 5/1

5:55 am-3:50 pm

1 stop10h 55m

Lambert-St Louis

Sun 5/3

6:15 am-5:25 pm

2 stops10h 10m

$458

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Tue 4/28

1:10 pm-7:31 pm

1 stop7h 21m

Lambert-St Louis

Sat 5/2

8:45 am-11:55 am

Nonstop2h 10m

$465

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/16

Showing 1-10 of 22 resultsSorted by cheapest first
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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 March.
ProviderPrice AccuracyTrust Score*
ExpediaPrice Accuracy1 starTrust Score*3 stars
FlightHubPrice Accuracy3 starsTrust Score*3 stars
eDreamsPrice Accuracy3 starsTrust 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 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.
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

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 $124). Flying from Washington, D.C. Dulles Intl Airport to St. Louis in March is currently the most expensive (average of $339). 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?

Find hourly flight availability from Dulles Intl to St. Louis. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated March 17, 2026.

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.

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
Our travel experts
Taryn White

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.

Read more
Ramsey Qubein

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.

Read more

Reviews of airlines servicing St. Louis

Get insights into the airlines that provide service to St. Louis. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to St. Louis. Reviews last updated March 17, 2026.
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
7.9
Good
8,288 reviews

Entertainment

7.8

Food

7.2

Overall

7.9

Boarding

8.1

Crew

8.5

Comfort

7.9

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
Delta
7.9
Good
8,288 reviews
Delta
7.9
Good
8,288 reviews

Entertainment

7.8

Food

7.2

Overall

7.9

Boarding

8.1

Crew

8.5

Comfort

7.9

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
United Airlines
7.4
Good
9,431 reviews
Delta
7.9
Good
8,288 reviews

Entertainment

7.8

Food

7.2

Overall

7.9

Boarding

8.1

Crew

8.5

Comfort

7.9

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
American Airlines
7.1
Good
11,466 reviews
Delta
7.9
Good
8,288 reviews

Entertainment

7.8

Food

7.2

Overall

7.9

Boarding

8.1

Crew

8.5

Comfort

7.9

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.
Frontier
5.7
Fair
3,027 reviews
Delta
7.9
Good
8,288 reviews

Entertainment

7.8

Food

7.2

Overall

7.9

Boarding

8.1

Crew

8.5

Comfort

7.9

Reviews

1 / 20
6.0
Good

Jim,Nov 2025

AVL - ATL

The exit row seats without a seat in front are great for leg room but don’t have a fold out entertainment console so you’re forced to use the screen several feet in front of you (there is, at least, a remote). Best to bring a tablet loaded with entertainment or a book.

Related info for your journey

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

  • 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 7 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 Southwest fly from Washington, D.C. Dulles Intl Airport to St. Louis in about 5h 02m. The time it takes to get you to your destination can typically vary by up to 1h 53m. 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 United Airlines, from $239. These flights start at 80% 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 ($99), and United Airlines ($117).

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

    Consider Republic Airways (100%), United Airlines (84%) or Lufthansa (77%) 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 $454, our data indicates the cheapest price to be $127. The most popular route (Washington, D.C. Dulles Intl - Lambert-St Louis), is priced around $233.

  • 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 $124). Flying from Washington, D.C. Dulles Intl Airport to St. Louis in March is currently the most expensive (average of $339). 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

Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
Edwardsville
O'Fallon
Fenton
Swansea
Fairview Heights
Maryland Heights
Collinsville
Eureka
Wentzville
Glencoe
Chesterfield
Alton
Farmington
Festus

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Top 4 airlines flying from Dulles Intl to St. Louis

Discover the top 4 airlines that operate flights from Dulles Intl to St. Louis. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated March 17, 2026.
AirlineCheapestAverageFlexibilityOn-time
FrontierCheapest$78Average$221FlexibilityNo cancel feeOn-time62%
DeltaCheapest$124Average$292FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$239Average$487FlexibilityNo cancel feeOn-time69%
American AirlinesCheapest$254Average$312FlexibilityNo cancel feeOn-time71%

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