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STL - IAD

Find cheap flights from St. Louis to Washington Dulles Airport from $89

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from St. Louis to Dulles Intl departing on 5/21. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
0 bags
Fri 5/24
Fri 5/31

Search hundreds of travel sites at once for deals on flights to Washington Dulles Airport

 
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Washington, D.C., as well as popular online travel agencies
These are the airlines KAYAK users have selected most often from within our search results in flight searches from St. Louis to Washington, D.C., as well as popular online travel agencies
In the last 7 days travelers have searched 44,632,927 times on KAYAK, and here is why:

Save 22% or moreCompare multiple travel sites with one search.

Track pricesNot ready to book? Create a price alert for when prices drop.

Filter your dealsChoose cabin class, free Wi-Fi and more.

Bundle and saveSave money when you bundle your flight + hotel.

Cheap flight deals from St. Louis to Dulles Intl (STL-IAD)

Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from St. Louis to Dulles Intl that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices and deals for you by selecting your travel dates.
Choose your dates
11:10 am - 4:23 pmSTL-IAD
4h 13m1 stop
8:32 am - 9:59 amIAD-STL
2h 27mnonstop
$191United Airlines
Find Deal
Wed, May 15 - Tue, May 21
11:10 am - 4:23 pmSTL-IAD
4h 13m1 stop
6:45 am - 10:14 amIAD-STL
4h 29m1 stop
$200United Airlines
Find Deal
Wed, May 15 - Tue, May 21
6:12 pm - 10:52 pmSTL-IAD
3h 40m1 stop
6:15 pm - 9:17 pmIAD-STL
4h 02m1 stop
$203Delta
Find Deal
Tue, Jun 4 - Sat, Jun 15
5:04 am - 11:15 amSTL-IAD
5h 11m1 stop
5:02 am - 9:53 amIAD-STL
5h 51m1 stop
$215American Airlines
Find Deal
Wed, May 22 - Wed, May 29
6:30 pm - 11:55 pmSTL-IAD
4h 25m1 stop
6:00 am - 9:19 amIAD-STL
4h 19m1 stop
$225Delta
Find Deal
Wed, May 15 - Sun, May 19
5:25 pm - 11:59 pmSTL-IAD
5h 34m1 stop
6:10 am - 9:15 amIAD-STL
4h 05m1 stop
$228Delta
Find Deal
Fri, Jun 28 - Sat, Jul 6
6:05 pm - 8:22 pmSTL-IAD
25h 17m1 stop
12:30 pm - 5:25 pmIAD-STL
5h 55m1 stop
$245Sun Country Air
Find Deal
Fri, May 24 - Sun, May 26
5:15 am - 12:43 pmSTL-IAD
6h 28m1 stop
1:22 pm - 4:56 pmIAD-STL
4h 34m1 stop
$249American Airlines
Find Deal
Wed, Jul 3 - Wed, Jul 10
2:35 pm - 11:20 amSTL-IAD
19h 45m3 stops
8:25 am - 10:28 amIAD-STL
27h 03m3 stops
Tue, May 7 - Fri, May 10
2:35 pm - 11:20 amSTL-IAD
19h 45m3 stops
1:25 pm - 3:14 pmIAD-STL
26h 49m2 stops
Tue, May 7 - Thu, May 9

Flights from St. Louis to Dulles Intl - Travel Insights & Trends

Get data-powered insights and trends into flights from St. Louis to Dulles Intl to help you find the cheapest flights, the best time to fly and much more.

What’s the cheapest day of the week to fly from St. Louis to Washington Dulles Airport?

The average price of all flights from St. Louis to Washington, D.C. Dulles Intl Airport clicked on KAYAK for each day over the last 12 months.
If you are looking for a flight deal from St. Louis to Washington Dulles Airport, look for departures on Tuesdays and avoid leaving on a Sunday, as it's usually the priciest day. When flying back from Washington Dulles Airport, Wednesday is the cheapest day to fly and Tuesday is the most expensive.

What is the cheapest month to fly from St. Louis to Washington, D.C. Dulles Intl Airport?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for flights from St. Louis to Washington, D.C. Dulles Intl Airport, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.
The cheapest month for flights from St. Louis to Washington, D.C. Dulles Intl Airport is January, where tickets cost $321 on average. On the other hand, the most expensive months are July and May, where the average cost of tickets is $446 and $440 respectively.

How far in advance should I book a flight from St. Louis to Washington, D.C. Dulles Intl Airport?

To calculate daily average prices, KAYAK takes all prices for each day before departure over the last year for flights from St. Louis to Washington, D.C. Dulles Intl Airport, removes the top 0.1% to account for outliers, and then takes the average of all the values for each month.
To get a below average price on the flight from St. Louis to Washington, D.C. Dulles Intl Airport, you should book around 2 weeks before departure. For the absolute cheapest price, our data suggests you should book 51 days before departure.

Which airlines provide the cheapest flights from St. Louis to Washington Dulles Airport?

The cheapest price for the route for each airline clicked by KAYAK users in the last 72 hours.
In the last 3 days, United Airlines offered the best one-way deal for that route, at $89. KAYAK users also found St. Louis to Washington Dulles Airport round-trip flights on United Airlines from $191 and on Delta from $203.

Which airlines fly non-stop between St. Louis and Washington, D.C. Dulles Intl Airport?

Airline and price data is aggregated from results in KAYAK’s search results from the last 2 weeks for flights from St. Louis to Washington, D.C. Dulles Intl Airport.
There is just one airline that flies from St. Louis to Washington, D.C. Dulles Intl Airport direct and that is United Airlines. The best one-way deal found from United Airlines for the route is $199.

How many flights are there between St. Louis and Washington, D.C. Dulles Intl Airport per day?

Each day, there are 2 nonstop flights that take off from St. Louis and land in Washington, D.C. Dulles Intl Airport, with an average flight time of 2h 09m. The most common departure time is 8:00 am and most flights take off in the morning. Each week, there are 14 flights and there are the same amount of flights each day 2.

Which cabin class options are there for flights between St. Louis and Washington, D.C. Dulles Intl Airport?

The average price of flights for each cabin class for the route found by users searching on KAYAK over the last 2 weeks.
There are 4 cabin class options for the route. These are First, Business, Economy and Prem Economy. Perform a search on KAYAK to find the latest prices and availability for all cabin fares, which differ across airlines.

How long does a flight from St. Louis to Washington Dulles Airport take?

The average nonstop flight takes 2h 08m, covering a distance of 694 miles.

What’s the earliest departure time from St. Louis to Washington Dulles Airport?

Early birds can take the earliest flight from St. Louis at 8:25 am and will be landing in Washington, D.C. Dulles Intl Airport at 11:35 am.

What’s the latest departure time from St. Louis to Washington Dulles Airport?

If you prefer to fly at night, the latest flight from St. Louis to Washington, D.C. Dulles Intl Airport jets off at 1:00 pm and lands at 4:10 pm.

Good to know

Low season

February

High season

December

Cheapest flight

$89
Best time to beat the crowds with an average 11% drop in price.
Most popular time to fly with an average 4% increase in price.
Flight from St. Louis to Washington Dulles Airport

When to book flights from St. Louis to Dulles Intl

Are your dates flexible? Find out the best times to travel from St. Louis to Dulles Intl based on our flight data from the last year. Discover the cheapest month and even day to fly.
Estimated round-trip price
KAYAK looks at all historical flight data for each date to provide a predicted price for one-way trips or round-trips with a duration up to 40 days. While we try to provide actual minimum prices for each date, some prices are predictions and actual prices may differ.

FAQs for booking St. Louis to Washington Dulles Airport flights

  • What is the cheapest flight from St. Louis to Washington, D.C. Dulles Intl Airport?

    In the last 3 days, the lowest price for a flight from St. Louis to Washington, D.C. Dulles Intl Airport was $89 for a one-way ticket and $191 for a round-trip.

  • Do I need a passport to fly between St. Louis and Washington Dulles Airport?

    No

  • Which airports will I be using when flying from St. Louis to Washington Dulles Airport?

    When flying out of St. Louis you will be using Lambert-St Louis. You will be landing at Washington Dulles Airport, also known as Washington, D.C. Dulles Intl.

  • Which airlines offer Wi-Fi service onboard planes from St. Louis to Washington Dulles Airport?

    American Airlines, United Airlines, Lufthansa, Delta, and Alaska Airlines offer inflight Wi-Fi service on the St. Louis to Washington Dulles Airport flight route.

  • Which aircraft models fly most regularly from St. Louis to Washington Dulles Airport?

    The Canadair (Bombardier) Regional Jet CRJ-550 is the aircraft model that flies most regularly on the St. Louis to Washington Dulles Airport flight route.

  • Which airline alliances offer flights from St. Louis to Washington Dulles Airport?

    Star Alliance is the only airline alliance operating flights between St. Louis and Washington Dulles Airport.

  • On which days can I fly direct from St. Louis to Washington Dulles Airport?

    There are nonstop flights from St. Louis to Washington Dulles Airport on a daily basis.

  • Which is the best airline for flights from St. Louis to Washington, D.C., Delta or United Airlines?

    The two airlines most popular with KAYAK users for flights from St. Louis to Washington, D.C. are Delta and United Airlines. With an average price for the route of $291 and an overall rating of 8.0, Delta is the most popular choice. United Airlines is also a great choice for the route, with an average price of $439 and an overall rating of 7.4.

  • How does KAYAK find such low prices on flights from St. Louis to Washington Dulles Airport?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights from St. Louis to Washington Dulles Airport.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket from St. Louis to Washington Dulles Airport?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Washington Dulles Airport from St. Louis is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights from St. Louis to Washington Dulles Airport?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Washington Dulles Airport with an airline and back to St. Louis with another airline. Booking your flights between St. Louis and IAD can sometimes prove cheaper using this method.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight from St. Louis to Washington Dulles Airport?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Washington Dulles Airport from St. Louis up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

See more FAQs

Top tips for finding a cheap flight from STL to Washington Dulles Airport

  • Looking for a cheap flight? 25% of our users found flights on this route for $249 or less one-way and $703 or less round-trip.

Prefer to fly non-stop from St. Louis to Washington Dulles Airport?

Find which airlines fly direct from Lambert-St Louis to Dulles Intl, which days they fly and book direct flights.

Nonstop departures

Lambert-St Louis to Washington, D.C. Dulles Intl

Monday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Tuesday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Wednesday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Thursday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Friday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Saturday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Sunday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

See more direct flights

Nonstop returns

Washington, D.C. Dulles Intl to Lambert-St Louis

Monday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Tuesday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Wednesday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Thursday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Friday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Saturday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

Sunday

Avianca, Brussels Airlines, Copa Airlines, +3 more

Avianca, Brussels Airlines, +4 more

See more direct flights
See more direct flights

Top 3 airlines serving from St. Louis to Dulles Intl

 
See real verified KAYAK customer reviews for airlines flying from St. Louis to Washington, D.C.. Airline scores are aggregated from all reviews left by passengers on KAYAK after flying with an airline. KAYAK doesn’t show reviews that are older than 5 years. Learn how KAYAK collects reviews.
Need help choosing which airline to fly with from St. Louis to Dulles Intl? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
8.0
DeltaOverall score based on 11004 reviews
8.0entertainment
8.2boarding
7.5food
7.9comfort
8.6crew
Airline reviews

On my way home I had a layover. The flight from ATL to CLT was amended 5x while I was waiting. I could have driven home sooner. Overall from Dallas, Tx to Charlotte, NC I started my trip at 4:30pm, I didn’t get home until past midnight. I know things happen, but 5x to make me run back and forth in an airport from different terminals is excessive. I also upgraded to comfort + , I didn’t feel it was worth it. There was no benefit

2.0 MediocreMarisol, Apr 2024DFW - ATL
Read more about Delta reviews

On my way home I had a layover. The flight from ATL to CLT was amended 5x while I was waiting. I could have driven home sooner. Overall from Dallas, Tx to Charlotte, NC I started my trip at 4:30pm, I didn’t get home until past midnight. I know things happen, but 5x to make me run back and forth in an airport from different terminals is excessive. I also upgraded to comfort + , I didn’t feel it was worth it. There was no benefit

On my way home I had a layover. The flight from ATL to CLT was amended 5x while I was waiting. I could have driven home sooner. Overall from Dallas, Tx to Charlotte, NC I started my trip at 4:30pm, I didn’t get home until past midnight. I know things happen, but 5x to make me run back and forth in an airport from different terminals is excessive.

They did a fine job. Can't wait to use Delta in the future.

There was a loud squeaky sound the whole time we were flying.

Had a broken tray in business class. Crew just shrugged it off.

Seat back monitors and outlets were dead and not working.

Everything was great except for the seat. The backrest would not stay in the upright position.

I usually have a positive experience with Delta. Complimentary upgrades are always nice!

Flight delayed about 2 hrs so it made it a VERY late night

It was a crowded flight. They did the best they could.

It got me where I needed it to; not much more. It had no competition so that was why I chose it.

Plane didn’t even make it off the ground. We all had to get off and walk to a different terminal (lots of confusion) to get on a different plane. Landed fairly late, connections missed.

Crowded flight, but upbeat and kind crew. Pilot greeted us at door, flight attendant thanked a number of “special” passengers for their business, another addressed an eight-year old boy as “young man.” United obviously trying to up their game, but though all of that is nice and notable, flying still feels like moving along a human assembly line, being herded into one small space after another (boarding areas with too few seats, planes with limited personal space, shuttles (IAD) packed too full.

It was ok until we got to DC and I wanted to use my United Club pass and the snobbish receptionist said that they don’t take one pass. It took me everything itch of patience not to tell her off

Food choice was poor and we had to buy on board snacks.

We were offer chocolate cookies , not everyone eat chocolate. Thank you

Lost luggage again. Our second trip to Mykonos, and 2nd time no luggage.

Flight was well orchestrated, made up time despite circling a bit all good on United. Travelers can just be so into themselves that common courtesy has gone out window for some, but that’s not on United.

Loading was quick and efficient. The bate and switch with discount tickets were you are forced to pay for bag.

Good flight, comfortable seats and very quick passage through Heathrow. Boarding in Washington was cramped and not well organized, but the rest was perfect.

The Flight attendant had an attitude and didn't allow anyone any time to prepare for landing despite being absent throughout the entire trip

American Airlines continues to price it can provide the least comfortable passenger experience in the air. This legacy carrier rivals the budgets for both terrible seats and inadequate amenities. I am a 5’7” woman who is not wider than a coach seat (even on these narrow bodied aircraft). My 3.5 hour flight was terribly uncomfortable because the leg room is inadequate (my knees hit the seat on front of me even when it was not reclined); the seat barely reclines; and the foam padding is worn thin to the extent one can feel the metal supports of the seat. Add to this the fact that the aisle is super narrow, so that the drink cart literally scrapes the arm rest of the aisle seat. It’s basically torture.

The flight was great until towards the end when the flight attendant read an excessively long commercial for purchasing an american airlines credit card. The worst part is that we are doing a lot of traveling this year so i was actually interested in getting the credit card, but I was so annoyed with the long commercial that I completely dismissed the flight attendant bringing around the information. Next time, keep the sales pitch to 10 seconds and then pass around the brochures!!

Nice aircraft. Plane was PACKED full and distance between seats was tight. Had it been more than a two hour flight it would not have been tolerable. I had much more knee space on the JetBlue flight I went out on.

New ridiculous policy by american destroyed my allegiance to american. As a million miler with american, I expected it would be easy to get on an earlier flight when I got to airport earlier than expected, and save a five hour layover. WRONG. The online app would not let me switch flights, So I called, and was promised a call back in 90 minutes. HAH! The customer service desk at DCA said “we no longer have access to changing a flight on our screens. If the app couldn’t do it, I should send a letter to American, but there’s nothing else possible!”

I am tired of being nickel and dimed for seat location, checked luggage and carry on bags. That is why i rarely fly anymore.

It was right on time and crew were very courteous

Great flight. Boarding was efficient and quick. On time departure and smooth flight. Flight arrived early at destination. Good experience.

Literally the worst experience ever and I had my service dog with me. Flight was supposed to leave at 1:51 PM but the plane arrived late. They boarded us around 3 PM and kept us on the plane for an hour saying that due to weather conditions in Miami, we could not takeoff yet. After waiting for an hour, they deplaned. And then they will not give us our bags back that we could just leave and schedule for another flight. Every hour they kept updating saying we have to wait another hour without any explanation as to what was going on. Eventually, I went to customer service to change my ticket, but by the time I made it to the front of the line, they started boarding my flight again. And then when we got onto the flight, they said there were two flight attendants That were past their shift. They kept us on the plane for about another 40 minutes until they told us they had no other flight attendance and had to deplane again. Then I gave us hotel vouchers and told us we would be on a flight at 6 AM the next day. At this point it is about 9 PM. I get to the hotel with my dog, who hasn’t been able to go potty for about eight hours. When I arrived at the hotel, I got a text alert saying my flight has been canceled at 6 AM and they moved past to 5 AM, however the hotel shuttle doesn’t leave early enough to make it to the airport for 5 AM flight. So me and some other passengers got a cab after about three hours of sleep to get back to the airport. This was the worst experience ever.

Their computers were down upon arrival to the airport. They were unable to figure out how to board us. We were delayed over an hour and a half.

Book cheap flights from St. Louis to Washington, D.C.

Recent one-way flight deals

 
Only flying one-way? Below are some of the best one-way flight deals from St. Louis to Washington, D.C. found on KAYAK in the last 72 hours.
5/21Tue
1 stopUnited Airlines
4h 43mSTL-IAD
$89
7/9Tue
1 stopDelta
7h 16mSTL-IAD
$104
8/9Fri
1 stopUnited Airlines
6h 00mSTL-IAD
$114
8/20Tue
nonstopUnited Airlines
2h 08mSTL-IAD
$130
5/16Thu
1 stopAmerican Airlines
5h 11mSTL-IAD
$135
8/9Fri
1 stopAmerican Airlines
6h 02mSTL-IAD
$137
6/27Thu
1 stopDelta
5h 34mSTL-IAD
$138
5/9Thu
2 stops
8h 16mSTL-IAD
$146
5/19Sun
1 stopSun Country Air
5h 12mSTL-IAD
$150
6/1Sat
1 stopDelta
4h 26mSTL-IAD
$154

Search by stops

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Last minute flights from St. Louis to Dulles Intl

Last minute flight, train and bus deals

 
These last-minute flight deals are the cheapest flights found on KAYAK in the last 72 hours for flights from St. Louis to Washington, D.C. that are departing in the next 10 days.
4/29Mon
multi-stopAmerican Airlines
5h 32mSTL-IAD
5/3Fri
multi-stopAmerican Airlines
6h 09mIAD-STL
$495
4/29Mon
multi-stopDelta
5h 21mSTL-IAD
5/2Thu
multi-stopDelta
5h 52mIAD-STL
$554
4/29Mon
nonstopUnited Airlines
2h 10mSTL-IAD
5/2Thu
nonstopUnited Airlines
2h 27mIAD-STL
$555
4/25Thu
nonstopUnited Airlines
2h 10mSTL-IAD
4/28Sun
nonstopUnited Airlines
2h 27mIAD-STL
$563
4/29Mon
nonstopUnited Airlines
2h 10mSTL-IAD
5/2Thu
multi-stopUnited Airlines
4h 29mIAD-STL
$564
4/26Fri
nonstopUnited Airlines
2h 10mSTL-IAD
4/28Sun
multi-stopUnited Airlines
6h 57mIAD-STL
$572
4/29Mon
multi-stopUnited Airlines
5h 34mSTL-IAD
5/3Fri
multi-stopUnited Airlines
5h 26mIAD-STL
$574
4/26Fri
multi-stopAmerican Airlines
5h 32mSTL-IAD
4/29Mon
multi-stopAmerican Airlines
4h 50mIAD-STL
$579
4/26Fri
multi-stopDelta
4h 53mSTL-IAD
4/28Sun
multi-stopDelta
4h 31mIAD-STL
$582
4/27Sat
multi-stopUnited Airlines
4h 46mSTL-IAD
4/29Mon
multi-stopUnited Airlines
22h 24mIAD-STL
$629

Search by stops

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St. Louis - Washington Dulles Airport Flights

Departure:

St. Louis (STL)United States

Destination:

Washington Dulles Airport (IAD)United States

Return flight deals:

Washington Dulles Airport - St. Louis

Cabin classes:

$2,004
$2,597
$1,539
$387