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Cheap flights from Washington, D.C. Dulles Intl Airport to St. Louis from $59

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 3/11. 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.
Delta Logo
6:00 am - 11:02 am
IAD
-
STL
6h 02m
1 stop
Delta Logo
5:50 pm - 11:09 pm
STL
-
IAD
4h 19m
1 stop
$253Delta
sáb., feb. 21 - mié., feb. 25
Frontier Logo
3:15 pm - 10:30 am
IAD
-
STL
20h 15m
1 stop
Frontier Logo
4:54 pm - 5:31 pm
STL
-
IAD
23h 37m
1 stop
$254Frontier
mié., abr. 1 - lun., abr. 6
Frontier Logo
5:39 pm - 6:51 am
IAD
-
STL
14h 12m
1 stop
Frontier Logo
3:49 pm - 7:20 am
STL
-
IAD
14h 31m
1 stop
$255Frontier
dom., feb. 15 - jue., feb. 19
Frontier Logo
8:30 pm - 7:51 am
IAD
-
STL
12h 21m
1 stop
Frontier Logo
8:16 pm - 12:36 am
STL
-
IAD
27h 20m
2 stops
$256Frontier
vie., abr. 3 - lun., abr. 6
Multiple Airlines Logo
2:58 pm - 11:19 pm
IAD
-
STL
9h 21m
2 stops
Multiple Airlines Logo
7:52 am - 7:24 am
STL
-
IAD
22h 32m
1 stop
$257Multiple Airlines
vie., mar. 6 - dom., mar. 8
Frontier Logo
2:39 pm - 8:10 pm
IAD
-
STL
6h 31m
1 stop
Frontier Logo
9:05 pm - 1:44 pm
STL
-
IAD
15h 39m
1 stop
$258Frontier
dom., mar. 8 - jue., mar. 12
Frontier Logo
10:10 am - 7:02 am
IAD
-
STL
21h 52m
1 stop
Frontier Logo
9:05 pm - 1:44 pm
STL
-
IAD
15h 39m
1 stop
$259Frontier
jue., mar. 5 - dom., mar. 8
Frontier Logo
11:44 am - 6:51 am
IAD
-
STL
20h 07m
1 stop
Frontier Logo
8:20 pm - 10:42 am
STL
-
IAD
13h 22m
1 stop
$260Frontier
jue., feb. 12 - vie., feb. 13
United Airlines Logo
6:45 pm - 8:23 pm
IAD
-
STL
2h 38mnonstop
United Airlines Logo
8:30 am - 11:40 am
STL
-
IAD
2h 10mnonstop
$262United Airlines
mar., feb. 24 - mar., mar. 3
Multiple Airlines Logo
2:58 pm - 11:19 pm
IAD
-
STL
9h 21m
2 stops
Multiple Airlines Logo
11:32 am - 12:21 am
STL
-
IAD
11h 49m
1 stop
$265Multiple Airlines
lun., mar. 16 - mié., mar. 18

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

Our best Delta deals on Washington, D.C. Dulles Intl Airport to St. Louis flight tickets
Delta
Mar 4
IAD6:00 amWashington, D.C. Dulles Intl
6h 02m
1 stop
STL11:02 amLambert-St Louis
May 27
STL5:30 pmLambert-St Louis
5h 39m
1 stop
IAD12:09 amWashington, D.C. Dulles Intl
$284
Delta
Apr 17
IAD5:07 pmWashington, D.C. Dulles Intl
4h 35m
1 stop
STL8:42 pmLambert-St Louis
Apr 21
STL6:50 pmLambert-St Louis
4h 52m
1 stop
IAD12:42 amWashington, D.C. Dulles Intl
$306
Delta
Apr 17
IAD6:00 amWashington, D.C. Dulles Intl
4h 42m
1 stop
STL9:42 amLambert-St Louis
Apr 20
STL9:59 amLambert-St Louis
5h 32m
1 stop
IAD4:31 pmWashington, D.C. Dulles Intl
$323

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
Apr 1
IAD3:15 pmWashington, D.C. Dulles Intl
20h 15m
1 stop
STL10:30 amLambert-St Louis
Apr 6
STL4:54 pmLambert-St Louis
23h 37m
1 stop
IAD5:31 pmWashington, D.C. Dulles Intl
$254
Frontier
Feb 15
IAD5:39 pmWashington, D.C. Dulles Intl
14h 12m
1 stop
STL6:51 amLambert-St Louis
Feb 19
STL3:49 pmLambert-St Louis
14h 31m
1 stop
IAD7:20 amWashington, D.C. Dulles Intl
$255
Frontier
Apr 3
IAD8:30 pmWashington, D.C. Dulles Intl
12h 21m
1 stop
STL7:51 amLambert-St Louis
Apr 6
STL8:16 pmLambert-St Louis
27h 20m
2 stops
IAD12:36 amWashington, D.C. Dulles Intl
$256

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 enero 29, 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

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

sáb. 2/21

6:00 am-11:02 am

1 stop6h 02m

Lambert-St Louis

mié. 2/25

5:50 pm-11:09 pm

1 stop4h 19m

$253

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

mié. 4/1

3:15 pm-10:30 am

1 stop20h 15m

Lambert-St Louis

lun. 4/6

4:54 pm-5:31 pm

1 stop23h 37m

$254

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

dom. 2/15

5:39 pm-6:51 am

1 stop14h 12m

Lambert-St Louis

jue. 2/19

3:49 pm-7:20 am

1 stop14h 31m

$255

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

vie. 4/3

8:30 pm-7:51 am

1 stop12h 21m

Lambert-St Louis

lun. 4/6

8:16 pm-12:36 am

2 stops27h 20m

$256

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

vie. 3/6

2:58 pm-11:19 pm

2 stops9h 21m

Lambert-St Louis

dom. 3/8

7:52 am-7:24 am

1 stop22h 32m

$257

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

dom. 3/8

2:39 pm-8:10 pm

1 stop6h 31m

Lambert-St Louis

jue. 3/12

9:05 pm-1:44 pm

1 stop15h 39m

$258

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

jue. 3/5

10:10 am-7:02 am

1 stop21h 52m

Lambert-St Louis

dom. 3/8

9:05 pm-1:44 pm

1 stop15h 39m

$259

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

jue. 2/12

11:44 am-6:51 am

1 stop20h 07m

Lambert-St Louis

vie. 2/13

8:20 pm-10:42 am

1 stop13h 22m

$260

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

mar. 2/24

6:45 pm-8:23 pm

Nonstop2h 38m

Lambert-St Louis

mar. 3/3

8:30 am-11:40 am

Nonstop2h 10m

$262

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

lun. 3/16

2:58 pm-11:19 pm

2 stops9h 21m

Lambert-St Louis

mié. 3/18

11:32 am-12:21 am

1 stop11h 49m

$265

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 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 $331. 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 $409. 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 $309 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 $378 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 January 2026, prices for Washington, D.C. Dulles Intl Airport to St. Louis flights are approximately 3% 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

$113

Fastest flight time

2h 23m

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 $113. 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 $399.
The fastest flight from Washington, D.C. Dulles Intl Airport to St. Louis takes 2h 23m
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 23m.

  • 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
3,056 reviews
Search Frontier flights
DeltaPriceFrom $124Free CancellationRating
7.9
8,127 reviews
Search Delta flights
United AirlinesPriceFrom $233Free CancellationRating
7.4
9,215 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 $233 round-trip, up to an average price of $453. 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
Florissant
O'Fallon
Collinsville
Fenton
St. Peters
Wentzville
Alton
Farmington
Clayton
Edwardsville
Eureka
Festus
Glencoe
Litchfield
Shrewsbury

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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