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Cheap flights from Washington, D.C. Dulles Intl Airport to St. Louis from $90

This is the cheapest one-way flight price found by a momondo user in the last 72 hours by searching for a flight from Washington, D.C. Dulles Intl Airport to St. Louis departing on 5/25. Fares may change, and may not be available for all flights or travel dates. Click the price to refresh the search for this deal.
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Find the cheapest flights from Washington, D.C. Dulles Intl Airport to St. Louis

Cheap round-trip flights

KAYAK's recommended round-trip deals from the most popular airlines that fly from Washington, D.C. Dulles Intl Airport to St. Louis.
United Airlines Logo
3:35 pm - 7:37 pmIAD-STL
5h 02m1 stop
United Airlines Logo
8:15 am - 11:23 amSTL-IAD
2h 08mnonstop
$189United Airlines
Find Deal
Sat, May 24 - Wed, May 28
Frontier Logo
5:25 pm - 12:04 amIAD-STL
7h 39m1 stop
Frontier Logo
5:41 pm - 4:36 pmSTL-IAD
21h 55m1 stop
$191Frontier
Find Deal
Mon, Apr 28 - Wed, Apr 30
Frontier Logo
8:01 am - 9:05 pmIAD-STL
14h 04m1 stop
Frontier Logo
5:45 pm - 4:36 pmSTL-IAD
21h 51m1 stop
$193Frontier
Find Deal
Mon, May 5 - Wed, May 7
Frontier Logo
5:25 pm - 12:04 amIAD-STL
7h 39m1 stop
Frontier Logo
5:41 pm - 4:36 pmSTL-IAD
21h 55m1 stop
$194Frontier
Find Deal
Mon, Apr 28 - Wed, Apr 30
Delta Logo
10:09 am - 4:35 pmIAD-STL
7h 26m1 stop
Delta Logo
6:45 am - 12:06 pmSTL-IAD
4h 21m1 stop
$217Delta
Find Deal
Sat, May 24 - Sun, May 25
Delta Logo
6:00 am - 9:00 amIAD-STL
4h 00m1 stop
Delta Logo
6:00 am - 11:58 amSTL-IAD
4h 58m1 stop
$233Delta
Find Deal
Thu, May 29 - Tue, Jun 3
American Airlines Logo
5:26 pm - 9:26 pmIAD-STL
5h 00m1 stop
American Airlines Logo
7:10 am - 1:22 pmSTL-IAD
5h 12m1 stop
$267American Airlines
Find Deal
Wed, May 14 - Wed, May 21
American Airlines Logo
5:02 am - 8:56 amIAD-STL
4h 54m1 stop
American Airlines Logo
6:47 pm - 12:02 amSTL-IAD
4h 15m1 stop
$282American Airlines
Find Deal
Fri, May 9 - Tue, May 13
 Logo
12:49 pm - 11:37 amIAD-STL
23h 48m1 stop
 Logo
9:50 am - 2:39 pmSTL-IAD
27h 49m2 stops
Thu, May 15 - Fri, May 23
 Logo
12:49 pm - 9:15 amIAD-STL
45h 26m3 stops
 Logo
9:50 am - 2:39 pmSTL-IAD
27h 49m2 stops
Thu, May 15 - Fri, May 23

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

Our best American Airlines deals on Washington, D.C. Dulles Intl Airport to St. Louis flight tickets
American Airlines
May 14
IAD5:26 pmWashington, D.C. Dulles Intl
5h 00m
1 stop
STL9:26 pmLambert-St Louis
May 21
STL7:10 amLambert-St Louis
5h 12m
1 stop
IAD1:22 pmWashington, D.C. Dulles Intl
American Airlines
May 9
IAD5:02 amWashington, D.C. Dulles Intl
4h 54m
1 stop
STL8:56 amLambert-St Louis
May 13
STL6:47 pmLambert-St Louis
4h 15m
1 stop
IAD12:02 amWashington, D.C. Dulles Intl
American Airlines
Jun 14
IAD8:14 pmWashington, D.C. Dulles Intl
4h 45m
1 stop
STL11:59 pmLambert-St Louis
Jun 15
STL5:30 amLambert-St Louis
6h 08m
1 stop
IAD12:38 pmWashington, D.C. Dulles Intl

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

Our best United Airlines deals on Washington, D.C. Dulles Intl Airport to St. Louis flight tickets
United Airlines
May 24
IAD3:35 pmWashington, D.C. Dulles Intl
5h 02m
1 stop
STL7:37 pmLambert-St Louis
May 28
STL8:15 amLambert-St Louis
2h 08m
IAD11:23 amWashington, D.C. Dulles Intl
United Airlines
May 24
IAD5:10 pmWashington, D.C. Dulles Intl
6h 35m
1 stop
STL10:45 pmLambert-St Louis
May 28
STL7:20 amLambert-St Louis
6h 07m
1 stop
IAD2:27 pmWashington, D.C. Dulles Intl
United Airlines
Jun 24
IAD6:48 amWashington, D.C. Dulles Intl
6h 32m
1 stop
STL12:20 pmLambert-St Louis
Jul 1
STL8:15 amLambert-St Louis
2h 08m
IAD11:23 amWashington, D.C. Dulles Intl

See travel insights to St. Louis from

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

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

What is the cheapest month to fly to St. Louis?

In general, February is the cheapest month to fly from Washington, D.C. Dulles Intl Airport to St. Louis. Due to it being the ‘off-season’ during this time, you can expect flight prices to be around $325. The month of July is another great option to travel to St. Louis, with average flight prices from Washington, D.C. Dulles Intl Airport averaging around $368.

What is the cheapest day to depart on your flight to St. Louis?

The cheapest day to depart on your flight to St. Louis is on a Wednesday when prices can be found for as low as $354. This is often the case because there is less demand to fly during this day of the week. If your travel schedule is flexible, try to avoid departing on a Sunday because tickets tend to average around $399. These prices are subject to change though, so be sure to set up a Price Alert for flights to St. Louis.

What is the cheapest time of day to depart on your flight to St. Louis?

Flying to St. Louis from Washington, D.C. Dulles Intl Airport at noon is the least expensive time of day to depart. momondo users have found prices as low as $313 when looking at flights departing at noon. In the morning is when there is more demand to fly to St. Louis, so prices are often more expensive at around $393 per ticket.

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

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

How far in advance should I book a flight to St. Louis?

You are more likely to see cheaper flights to St. Louis from Washington, D.C. Dulles Intl Airport when booking 8 weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $418 when searching 8 weeks out.However, flight prices might be lower outside of this timeframe. For example, people recently found flights to St. Louis from Washington, D.C. Dulles Intl Airport for as low as $276 on momondo.

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

There are 4 cabin classes available to choose from on Washington, D.C. Dulles Intl to Lambert-St Louis flights. Cabin price and availability will vary by airline so perform a search above to find the right deals for you.

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

As of April 2025, prices for Washington, D.C. Dulles Intl Airport to St. Louis flights are approximately 58% cheaper when compared to flights at the same time last year.

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

Are you open to changing your travel dates? Check out the ideal times to fly from Washington, D.C. Dulles Intl Airport to St. Louis according to our flight data. Find out which month and days have the cheapest flights.
Estimated round-trip price

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

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

Best Price Found

$90

Fastest flight time

2h 16m

Direct flights

Every day

Airports in St. Louis

1 airport
The best one-way flight to St. Louis from Washington, D.C. Dulles Intl Airport in the past 72 hours is $90. The best round-trip flight deal from Washington, D.C. Dulles Intl Airport to St. Louis found on momondo in the last 72 hours is $189.
The fastest flight from Washington, D.C. Dulles Intl Airport to St. Louis takes 2h 16m
Direct flights go from Washington, D.C. Dulles Intl Airport to St. Louis every day.
There is 1 airport near St. Louis: Lambert-St Louis (STL)

  • How far is Washington, D.C. Dulles Intl to Lambert-St Louis by plane?

    The straight-line distance from Washington, D.C. Dulles Intl to Lambert-St Louis is 685.9 mi. By plane, this route typically takes 2h 16m.

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

    Prices for flights from Washington, D.C. Dulles Intl Airport to Lambert-St Louis Airport are updated daily.

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

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

    The minimum age for a child to fly alone is five, but airlines that offer an unaccompanied minor (UNMR) service may have their own age limitations. Flight duration, scheduling, and layovers are among the considerations that may influence age limits. We recommend that you double-check with the airline you are booking with for travel from Washington, D.C. Dulles Intl Airport to Lambert-St Louis Airport.

  • What documentation or ID do you need to fly to Lambert-St Louis Airport?

    The travel and health documents required for your trip to Lambert-St Louis Airport can vary based on your itinerary and personal situation. As a rule, consider having multiple documents such as a national ID card or driver’s license, and a passport valid for six-months after you plan to arrive at Lambert-St Louis Airport. We always recommend checking with your airline or a trusted third party such as IATA to get advice.

  • What is the most popular plane model from Washington, D.C. Dulles Intl Airport to St. Louis?

  • What is the most popular airline from Washington, D.C. Dulles Intl Airport to St. Louis?


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

Compare and see reviews for airlines that fly from Washington, D.C. Dulles Intl Airport to St. Louis with momondo
Airline
Rating
Free Cancellation
Price
DeltaPriceFrom $198Free CancellationRating
8.0
7,916 reviews
Search Delta flights
American AirlinesPriceFrom $255Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
United AirlinesPriceFrom $263Free CancellationRating
7.4
8,667 reviews
Search United Airlines flights
  • United Airlines Flights From Washington, D.C. Dulles Intl Airport to St. Louis

    United Airlines is one of the most popular airlines flying from Washington, D.C. Dulles Intl Airport to St. Louis, operating 14 flights/week on average for this route. A good United Airlines flight deal for Washington, D.C. Dulles Intl Airport to St. Louis starts from $263 round-trip, up to an average price of $490. Our users have rated United Airlines at 7.4/10.


Traveling to a place near St. Louis?

Book flights to St. Louis if you plan to visit one of these locations
St. Charles
Chesterfield
Florissant
Maryland Heights
Hermann
Fairview Heights
Collinsville
Fenton
Farmington
O'Fallon
St. Peters
Wentzville
Alton
Glencoe
Eureka
Edwardsville
Festus
Clayton
Grafton
Litchfield

Why use momondo?

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

It is quick and easy to find Washington, D.C. to St. Louis flights on momondo. We search and return numerous flight options from various airlines and agents. You can then use our filters to narrow your search until you have found the most convenient flight to St. Louis that suits you.

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

Yes. All flights to St. Louis from Washington, D.C. on momondo can be compared and filtered by various policies on offer, including flexible booking.

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

momondo provides multiple filters to help you find the best flight to St. Louis from Washington, D.C.. Filter by price, airline, airports, cabin, aircraft, payment method, number of stops and more.

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

Yes momondo offers price alerts on flights to St. Louis from Washington, D.C.. After performing a search on this page you should be able to see the price alert set up feature. Simply provide a valid email address and momondo will instantly alert you when prices change.


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