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Cheap flights from Washington, D.C. Dulles Intl Airport to St. Louis 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 Washington, D.C. Dulles Intl Airport to St. Louis departing on 4/26. 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

Enter your travel dates to find the best prices.
United Airlines Logo
3:15 pm - 9:13 pm
IAD
-
STL
6h 58m
1 stop
United Airlines Logo
8:45 am - 11:55 am
STL
-
IAD
2h 10mnonstop
$275United Airlines
wo, mei. 6 - za, mei. 9
Frontier Logo
6:27 pm - 4:54 pm
IAD
-
STL
23h 27m
1 stop
Frontier Logo
8:08 pm - 10:12 am
STL
-
IAD
13h 04m
2 stops
$276Frontier
wo, mei. 6 - za, mei. 9
Frontier Logo
6:10 am - 7:21 pm
IAD
-
STL
14h 11m
2 stops
Frontier Logo
8:23 pm - 9:54 am
STL
-
IAD
12h 31m
1 stop
$277Frontier
do, apr. 16 - vr, apr. 17
Frontier Logo
11:07 am - 4:54 pm
IAD
-
STL
6h 47m
1 stop
Frontier Logo
4:19 pm - 6:42 pm
STL
-
IAD
25h 23m
1 stop
$278Frontier
do, mei. 14 - zo, mei. 17
Southwest Logo
5:55 pm - 11:50 pm
IAD
-
STL
6h 55m
1 stop
Southwest Logo
6:10 am - 4:25 pm
STL
-
IAD
9h 15m
2 stops
$279Southwest
do, apr. 23 - za, apr. 25
Frontier Logo
7:40 am - 12:21 am
IAD
-
STL
17h 41m
2 stops
Frontier Logo
5:27 pm - 10:12 am
STL
-
IAD
15h 45m
1 stop
$280Frontier
vr, mei. 15 - wo, mei. 20
Multiple Airlines Logo
2:58 pm - 11:19 pm
IAD
-
STL
9h 21m
2 stops
Multiple Airlines Logo
8:23 pm - 8:56 am
STL
-
IAD
11h 33m
1 stop
$281Multiple Airlines
vr, apr. 17 - za, apr. 18
United Airlines Logo
5:41 pm - 11:57 pm
IAD
-
STL
7h 16m
1 stop
United Airlines Logo
8:30 am - 11:43 am
STL
-
IAD
2h 13mnonstop
$284United Airlines
vr, apr. 17 - za, apr. 18
Delta Logo
3:00 pm - 7:11 pm
IAD
-
STL
5h 11m
1 stop
Delta Logo
6:00 am - 11:50 am
STL
-
IAD
4h 50m
1 stop
$285Delta
za, mei. 2 - za, mei. 16
United Airlines Logo
5:50 pm - 7:27 pm
IAD
-
STL
2h 37mnonstop
United Airlines Logo
7:11 pm - 12:33 am
STL
-
IAD
4h 22m
1 stop
$286United Airlines
za, mei. 2 - za, mei. 16

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

Our best Frontier deals on Washington, D.C. Dulles Intl Airport to St. Louis flight tickets
Frontier
May 6
IAD6:27 pmWashington, D.C. Dulles Intl
23h 27m
1 stop
STL4:54 pmLambert-St Louis
May 9
STL8:08 pmLambert-St Louis
13h 04m
2 stops
IAD10:12 amWashington, D.C. Dulles Intl
$276
Frontier
Apr 16
IAD6:10 amWashington, D.C. Dulles Intl
14h 11m
2 stops
STL7:21 pmLambert-St Louis
Apr 17
STL8:23 pmLambert-St Louis
12h 31m
1 stop
IAD9:54 amWashington, D.C. Dulles Intl
$277
Frontier
May 14
IAD11:07 amWashington, D.C. Dulles Intl
6h 47m
1 stop
STL4:54 pmLambert-St Louis
May 17
STL4:19 pmLambert-St Louis
25h 23m
1 stop
IAD6:42 pmWashington, D.C. Dulles Intl
$278

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
Apr 28
IAD10:32 amWashington, D.C. Dulles Intl
12h 47m
2 stops
STL10:19 pmLambert-St Louis
Apr 29
STL2:12 pmLambert-St Louis
4h 13m
1 stop
IAD7:25 pmWashington, D.C. Dulles Intl
$306
American Airlines
Apr 5
IAD2:03 pmWashington, D.C. Dulles Intl
6h 27m
1 stop
STL7:30 pmLambert-St Louis
Apr 7
STL7:00 amLambert-St Louis
7h 23m
1 stop
IAD3:23 pmWashington, D.C. Dulles Intl
$610
American Airlines
Apr 9
IAD3:26 pmWashington, D.C. Dulles Intl
5h 04m
1 stop
STL7:30 pmLambert-St Louis
Apr 12
STL6:55 pmLambert-St Louis
4h 04m
1 stop
IAD11:59 pmWashington, D.C. Dulles Intl
$643

momondo Fare Finder

 
Customize your flight search to find flights from Washington, D.C. Dulles Intl Airport 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, momondo users made 832,500 searches. Data last updated maart 31, 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

wo 5/6

3:15 pm-9:13 pm

1 stop6h 58m

Lambert-St Louis

za 5/9

8:45 am-11:55 am

Nonstop2h 10m

$275

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

wo 5/6

6:27 pm-4:54 pm

1 stop23h 27m

Lambert-St Louis

za 5/9

8:08 pm-10:12 am

2 stops13h 04m

$276

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

do 4/16

6:10 am-7:21 pm

2 stops14h 11m

Lambert-St Louis

vr 4/17

8:23 pm-9:54 am

1 stop12h 31m

$277

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

do 5/14

11:07 am-4:54 pm

1 stop6h 47m

Lambert-St Louis

zo 5/17

4:19 pm-6:42 pm

1 stop25h 23m

$278

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

do 4/23

5:55 pm-11:50 pm

1 stop6h 55m

Lambert-St Louis

za 4/25

6:10 am-4:25 pm

2 stops9h 15m

$279

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

vr 5/15

7:40 am-12:21 am

2 stops17h 41m

Lambert-St Louis

wo 5/20

5:27 pm-10:12 am

1 stop15h 45m

$280

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

vr 4/17

2:58 pm-11:19 pm

2 stops9h 21m

Lambert-St Louis

za 4/18

8:23 pm-8:56 am

1 stop11h 33m

$281

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

vr 4/17

5:41 pm-11:57 pm

1 stop7h 16m

Lambert-St Louis

za 4/18

8:30 am-11:43 am

Nonstop2h 13m

$284

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

za 5/2

3:00 pm-7:11 pm

1 stop5h 11m

Lambert-St Louis

za 5/16

6:00 am-11:50 am

1 stop4h 50m

$285
Quickest round-trip

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

za 5/2

5:50 pm-7:27 pm

Nonstop2h 37m

Lambert-St Louis

za 5/16

7:11 pm-12:33 am

1 stop4h 22m

$286

Flights are sorted by cheapest round-trip flights first.

Showing 1-10 of 20 resultsSorted by cheapest first
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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 typical price of a round-trip flight between Washington, D.C. Dulles Intl Airport and St. Louis?

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

In general, August 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 $290. 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 $292.

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 Saturday when prices can be found for as low as $330. 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 $401. 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 in the evening is the least expensive time of day to depart. momondo users have found prices as low as $319 when looking at flights departing in the evening. In the afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $387 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

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 March 2026, prices for Washington, D.C. Dulles Intl Airport to St. Louis flights are approximately 6% more expensive 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

$208

Fastest flight time

2h 19m

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 $208. 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 $406.
The fastest flight from Washington, D.C. Dulles Intl Airport to St. Louis takes 2h 19m
Direct flights go from Washington, D.C. Dulles Intl Airport to St. Louis every day.
There is 1 airport in St. Louis. From Washington, D.C. Dulles Intl Airport there are direct flights to Lambert-St Louis (STL).
Search flight deals

  • 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 19m.

  • 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
FrontierPriceFrom $78Free CancellationRating
5.7
3,008 reviews
Search Frontier flights
DeltaPriceFrom $124Free CancellationRating
7.9
8,364 reviews
Search Delta flights
American AirlinesPriceFrom $254Free CancellationRating
7.1
11,543 reviews
Search American Airlines flights
United AirlinesPriceFrom $269Free CancellationRating
7.4
9,525 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 $269 round-trip, up to an average price of $508. 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
Hermann
Fairview Heights
Maryland Heights
O'Fallon
Florissant
St. Peters
Collinsville
Alton
Wentzville
Fenton
Farmington
Clayton
Festus
Eureka
Edwardsville
Litchfield
Shrewsbury
Grafton

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.

An easier way to manage your St. Louis trip

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