Cheap flights from Washington, D.C. Dulles Intl Airport to St. Louis from $72

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 10/23. 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

Frontier Logo
6:15 am - 10:16 amIAD-STL
5h 01m1 stop
Frontier Logo
10:18 am - 11:22 pmSTL-IAD
12h 04m2 stops
$210Frontier
Find Deal
Fri, Oct 24 - Mon, Oct 27
Frontier Logo
7:14 pm - 1:07 pmIAD-STL
18h 53m1 stop
Frontier Logo
4:00 pm - 12:15 amSTL-IAD
7h 15m1 stop
$212Frontier
Find Deal
Sat, Sep 27 - Mon, Sep 29
Frontier Logo
6:15 am - 10:37 amIAD-STL
5h 22m1 stop
Frontier Logo
10:18 am - 11:22 pmSTL-IAD
12h 04m2 stops
$214Frontier
Find Deal
Fri, Oct 17 - Mon, Oct 27
Frontier Logo
6:15 am - 10:37 amIAD-STL
5h 22m1 stop
Frontier Logo
4:33 pm - 7:17 pmSTL-IAD
25h 44m1 stop
$215Frontier
Find Deal
Fri, Oct 17 - Sat, Oct 18
Frontier Logo
6:15 am - 10:37 amIAD-STL
5h 22m1 stop
Frontier Logo
7:52 pm - 7:46 pmSTL-IAD
22h 54m2 stops
$216Frontier
Find Deal
Fri, Oct 10 - Mon, Oct 13
Multiple Airlines Logo
6:15 am - 10:37 amIAD-STL
5h 22m1 stop
Multiple Airlines Logo
10:57 am - 7:14 pmSTL-IAD
31h 17m2 stops
$265Multiple Airlines
Find Deal
Thu, Oct 16 - Sun, Oct 19
Delta Logo
6:00 am - 9:46 amIAD-STL
4h 46m1 stop
Delta Logo
6:00 am - 11:34 amSTL-IAD
4h 34m1 stop
$275Delta
Find Deal
Tue, Nov 25 - Fri, Nov 28
Delta Logo
7:05 am - 12:35 pmIAD-STL
6h 30m1 stop
Delta Logo
6:14 pm - 11:00 pmSTL-IAD
3h 46m1 stop
$277Delta
Find Deal
Tue, Oct 7 - Tue, Oct 7
Multiple Airlines Logo
9:15 am - 9:40 amIAD-STL
25h 25m2 stops
Multiple Airlines Logo
4:00 pm - 11:16 pmSTL-IAD
6h 16m1 stop
$284Multiple Airlines
Find Deal
Wed, Oct 1 - Mon, Oct 6
United Airlines Logo
8:40 am - 10:02 amIAD-STL
2h 22mnonstop
United Airlines Logo
3:23 pm - 8:55 pmSTL-IAD
4h 32m1 stop
$285United Airlines
Find Deal
Thu, Oct 9 - Sat, Oct 11

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
Oct 24
IAD6:15 amWashington, D.C. Dulles Intl
5h 01m
1 stop
STL10:16 amLambert-St Louis
Oct 27
STL10:18 amLambert-St Louis
12h 04m
2 stops
IAD11:22 pmWashington, D.C. Dulles Intl
Frontier
Sep 27
IAD7:14 pmWashington, D.C. Dulles Intl
18h 53m
1 stop
STL1:07 pmLambert-St Louis
Sep 29
STL4:00 pmLambert-St Louis
7h 15m
1 stop
IAD12:15 amWashington, D.C. Dulles Intl
Frontier
Oct 17
IAD6:15 amWashington, D.C. Dulles Intl
5h 22m
1 stop
STL10:37 amLambert-St Louis
Oct 27
STL10:18 amLambert-St Louis
12h 04m
2 stops
IAD11:22 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
Oct 9
IAD8:40 amWashington, D.C. Dulles Intl
2h 22m
STL10:02 amLambert-St Louis
Oct 11
STL3:23 pmLambert-St Louis
4h 32m
1 stop
IAD8:55 pmWashington, D.C. Dulles Intl
United Airlines
Sep 24
IAD8:40 amWashington, D.C. Dulles Intl
2h 22m
STL10:02 amLambert-St Louis
Oct 1
STL1:05 pmLambert-St Louis
2h 10m
IAD4:15 pmWashington, D.C. Dulles Intl
United Airlines
Sep 24
IAD8:40 amWashington, D.C. Dulles Intl
2h 22m
STL10:02 amLambert-St Louis
Sep 25
STL8:05 amLambert-St Louis
2h 10m
IAD11:15 amWashington, D.C. Dulles Intl

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 September 17, 2025.
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

Fri 10/24

6:15 am-10:16 am

1 stop5h 01m

Lambert-St Louis

Mon 10/27

10:18 am-11:22 pm

2 stops12h 04m

$210

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Sat 9/27

7:14 pm-1:07 pm

1 stop18h 53m

Lambert-St Louis

Mon 9/29

4:00 pm-12:15 am

1 stop7h 15m

$212

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Fri 10/17

6:15 am-10:37 am

1 stop5h 22m

Lambert-St Louis

Mon 10/27

10:18 am-11:22 pm

2 stops12h 04m

$214

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Fri 10/17

6:15 am-10:37 am

1 stop5h 22m

Lambert-St Louis

Sat 10/18

4:33 pm-7:17 pm

1 stop25h 44m

$215

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Fri 10/10

6:15 am-10:37 am

1 stop5h 22m

Lambert-St Louis

Mon 10/13

7:52 pm-7:46 pm

2 stops22h 54m

$216

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Thu 10/16

6:15 am-10:37 am

1 stop5h 22m

Lambert-St Louis

Sun 10/19

10:57 am-7:14 pm

2 stops31h 17m

$265

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Tue 11/25

6:00 am-9:46 am

1 stop4h 46m

Lambert-St Louis

Fri 11/28

6:00 am-11:34 am

1 stop4h 34m

$275

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Tue 10/7

7:05 am-12:35 pm

1 stop6h 30m

Lambert-St Louis

Tue 10/7

6:14 pm-11:00 pm

1 stop3h 46m

$277

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Wed 10/1

9:15 am-9:40 am

2 stops25h 25m

Lambert-St Louis

Mon 10/6

4:00 pm-11:16 pm

1 stop6h 16m

$284

Washington, D.C.St. Louis

IAD - STL

IADSTL

Washington, D.C. Dulles Intl

Thu 10/9

8:40 am-10:02 am

Nonstop2h 22m

Lambert-St Louis

Sat 10/11

3:23 pm-8:55 pm

1 stop4h 32m

$285

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 Wednesday when prices can be found for as low as $350. 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 $411. 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 afternoon is when there is more demand to fly to St. Louis, so prices are often more expensive at around $383 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 weeks ahead of your departure date. In general, you can expect to find flights to St. Louis for around $400 when searching 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 $260 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.

Can stopping save me money on Washington, D.C. Dulles Intl Airport to St. Louis flights?

No. A direct flight is the cheapest option for a flight between Washington, D.C. Dulles Intl Airport to St. Louis.

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

As of September 2025, prices for Washington, D.C. Dulles Intl Airport to St. Louis flights are approximately 12% 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

$415

Fastest flight time

2h 22m

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 $415. 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 $368.
The fastest flight from Washington, D.C. Dulles Intl Airport to St. Louis takes 2h 22m
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 22m.

  • 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 $196Free CancellationRating
7.9
7,961 reviews
Search Delta flights
United AirlinesPriceFrom $271Free CancellationRating
7.4
8,926 reviews
Search United Airlines flights
American AirlinesPriceFrom $276Free CancellationRating
7.2
10,000 reviews
Search American 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 $271 round-trip, up to an average price of $478. 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
Florissant
Maryland Heights
O'Fallon
Fenton
Collinsville
Wentzville
Alton
St. Peters
Farmington
Festus
Glencoe
Clayton
Edwardsville
Eureka
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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1 adult
Fri 10/17
Fri 10/24

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