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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 8/23. 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

United Airlines Logo
8:40 am - 10:02 amIAD-STL
2h 22mnonstop
United Airlines Logo
5:30 pm - 12:32 amSTL-IAD
6h 02m1 stop
$189United Airlines
Find Deal
jue., sep. 4 - lun., sep. 8
Frontier Logo
6:10 am - 1:59 pmIAD-STL
8h 49m1 stop
Frontier Logo
3:02 pm - 11:00 pmSTL-IAD
6h 58m1 stop
$196Frontier
Find Deal
sáb., ago. 16 - sáb., ago. 23
Delta Logo
6:00 am - 9:41 amIAD-STL
4h 41m1 stop
Delta Logo
9:17 am - 2:31 pmSTL-IAD
4h 14m1 stop
$199Delta
Find Deal
mar., ago. 5 - mié., ago. 13
Frontier Logo
4:24 pm - 1:59 pmIAD-STL
22h 35m1 stop
Frontier Logo
2:36 pm - 1:49 pmSTL-IAD
22h 13m1 stop
$209Frontier
Find Deal
vie., ago. 1 - dom., ago. 10
United Airlines Logo
8:40 am - 10:02 amIAD-STL
2h 22mnonstop
United Airlines Logo
5:30 pm - 12:32 amSTL-IAD
6h 02m1 stop
$212United Airlines
Find Deal
dom., sep. 7 - lun., sep. 8
Frontier Logo
6:10 am - 3:04 pmIAD-STL
9h 54m1 stop
Frontier Logo
4:00 pm - 12:06 amSTL-IAD
7h 06m1 stop
$213Frontier
Find Deal
jue., sep. 25 - lun., sep. 29
United Airlines Logo
8:40 am - 9:59 amIAD-STL
2h 19mnonstop
United Airlines Logo
5:30 pm - 12:32 amSTL-IAD
6h 02m1 stop
$214United Airlines
Find Deal
jue., ago. 14 - jue., ago. 21
United Airlines Logo
6:35 am - 12:27 pmIAD-STL
6h 52m1 stop
United Airlines Logo
8:15 am - 11:23 amSTL-IAD
2h 08mnonstop
$215United Airlines
Find Deal
mar., ago. 12 - sáb., ago. 16
Frontier Logo
6:10 am - 3:04 pmIAD-STL
9h 54m1 stop
Frontier Logo
4:00 pm - 12:46 pmSTL-IAD
19h 46m1 stop
$219Frontier
Find Deal
jue., sep. 18 - dom., sep. 21
Delta Logo
7:50 pm - 11:39 pmIAD-STL
4h 49m1 stop
Delta Logo
7:05 pm - 12:07 amSTL-IAD
4h 02m1 stop
$224Delta
Find Deal
lun., nov. 17 - vie., nov. 21

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
Sep 4
IAD8:40 amWashington, D.C. Dulles Intl
2h 22m
STL10:02 amLambert-St Louis
Sep 8
STL5:30 pmLambert-St Louis
6h 02m
1 stop
IAD12:32 amWashington, D.C. Dulles Intl
$189
Find similar
United Airlines
Sep 7
IAD8:40 amWashington, D.C. Dulles Intl
2h 22m
STL10:02 amLambert-St Louis
Sep 8
STL5:30 pmLambert-St Louis
6h 02m
1 stop
IAD12:32 amWashington, D.C. Dulles Intl
$212
Find similar
United Airlines
Aug 14
IAD8:40 amWashington, D.C. Dulles Intl
2h 19m
STL9:59 amLambert-St Louis
Aug 21
STL5:30 pmLambert-St Louis
6h 02m
1 stop
IAD12:32 amWashington, D.C. Dulles Intl
$214
Find similar

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
Aug 16
IAD6:10 amWashington, D.C. Dulles Intl
8h 49m
1 stop
STL1:59 pmLambert-St Louis
Aug 23
STL3:02 pmLambert-St Louis
6h 58m
1 stop
IAD11:00 pmWashington, D.C. Dulles Intl
$196
Find similar
Frontier
Aug 1
IAD4:24 pmWashington, D.C. Dulles Intl
22h 35m
1 stop
STL1:59 pmLambert-St Louis
Aug 10
STL2:36 pmLambert-St Louis
22h 13m
1 stop
IAD1:49 pmWashington, D.C. Dulles Intl
$209
Find similar
Frontier
Sep 25
IAD6:10 amWashington, D.C. Dulles Intl
9h 54m
1 stop
STL3:04 pmLambert-St Louis
Sep 29
STL4:00 pmLambert-St Louis
7h 06m
1 stop
IAD12:06 amWashington, D.C. Dulles Intl
$213
Find similar

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, July 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 $292. The month of May is another great option to travel to St. Louis, with average flight prices from Washington, D.C. Dulles Intl Airport averaging around $311.

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 $351. 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 in the evening is the least expensive time of day to depart. momondo users have found prices as low as $312 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 $384 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 $238 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 July 2025, prices for Washington, D.C. Dulles Intl Airport to St. Louis flights are approximately 27% 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 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 $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 19m
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)
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
DeltaPriceFrom $207Free CancellationRating
8.0
7,958 reviews
Search Delta flights
American AirlinesPriceFrom $214Free CancellationRating
7.2
10,000 reviews
Search American Airlines flights
United AirlinesPriceFrom $257Free CancellationRating
7.4
8,864 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 $257 round-trip, up to an average price of $479. 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
Collinsville
Fenton
O'Fallon
Farmington
Alton
St. Peters
Wentzville
Festus
Glencoe
Clayton
Edwardsville
Eureka
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.

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