IAD - STL

$55 Find Cheap Flights from Washington Dulles Airport to St. Louis

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight from Dulles Intl to St. Louis departing on 2/19. 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.
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These are the airlines KAYAK users have selected most often from within our search results in flight searches from Washington, D.C. to St. Louis, 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 Washington, D.C. to St. Louis, as well as popular online travel agencies
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Cheap Flight Deals from Washington Dulles Airport to St. Louis (IAD-STL)

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Washington Dulles Airport to St. Louis 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.

Recent round-trip flight deals from Dulles Intl to St. Louis

Recommended round-trip deals departing in the coming months from the most popular airlines that fly from Dulles Intl to St. Louis.
Discover the best prices and deals for you by selecting your travel dates.
Choose your dates
6:03 pm - 11:43 pmIAD-STL
6h 40m1 stop
5:20 pm - 4:54 pmSTL-IAD
22h 34m1 stop
$118Frontier
Find Deal
Wed, Feb 26 - Wed, Mar 5
6:03 pm - 11:43 pmIAD-STL
6h 40m1 stop
5:20 pm - 5:13 pmSTL-IAD
22h 53m1 stop
$120Frontier
Find Deal
Sat, Feb 15 - Tue, Feb 25
6:03 pm - 11:43 pmIAD-STL
6h 40m1 stop
5:20 pm - 5:13 pmSTL-IAD
22h 53m1 stop
$140Frontier
Find Deal
Sat, Feb 15 - Tue, Feb 18
8:35 am - 10:05 amIAD-STL
2h 30mnonstop
8:25 am - 11:34 amSTL-IAD
2h 09mnonstop
$179United Airlines
Find Deal
Sat, Feb 15 - Tue, Feb 25
8:35 am - 10:05 amIAD-STL
2h 30mnonstop
5:33 pm - 11:04 pmSTL-IAD
4h 31m1 stop
$189United Airlines
Find Deal
Sat, Feb 15 - Tue, Feb 25
6:00 am - 9:20 amIAD-STL
4h 20m1 stop
5:50 pm - 11:13 pmSTL-IAD
4h 23m1 stop
$198Delta
Find Deal
Thu, Feb 20 - Mon, Feb 24
6:00 am - 9:20 amIAD-STL
4h 20m1 stop
4:40 pm - 12:20 amSTL-IAD
6h 40m1 stop
$199Delta
Find Deal
Thu, Feb 20 - Mon, Feb 24
5:00 am - 8:30 amIAD-STL
4h 30m1 stop
7:03 pm - 11:57 pmSTL-IAD
3h 54m1 stop
$273American Airlines
Find Deal
Tue, Apr 22 - Tue, Apr 22
6:30 am - 12:59 pmIAD-STL
7h 29m1 stop
5:55 am - 4:58 pmSTL-IAD
10h 03m2 stops
$326American Airlines
Find Deal
Thu, Feb 27 - Thu, Mar 6
10:20 pm - 8:10 pmIAD-STL
22h 50m2 stops
12:15 pm - 11:13 pmSTL-IAD
9h 58m3 stops
$390Southern / Mokulele
Find Deal
Thu, Feb 20 - Mon, Feb 24

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

Get data-powered insights and trends into flights from Dulles Intl to St. Louis 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 Washington Dulles Airport to St. Louis?

The average price of all round-trip flights from Washington, D.C. Dulles Intl Airport to St. Louis clicked on KAYAK for each day over the last 12 months.
For Washington Dulles Airport to St. Louis, Sunday is the cheapest day to fly on average and Monday is the most expensive. Flying from St. Louis back to Washington Dulles Airport, the best deals are generally found on Friday, with Saturday being the most expensive.

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

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Washington, D.C. Dulles Intl Airport to St. Louis, 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 Washington, D.C. Dulles Intl Airport to St. Louis is February, where tickets cost $378 (return) on average. On the other hand, the most expensive months are December and January, where the average cost of round-trip tickets is $499 and $496 respectively.

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

To calculate weekly average prices, KAYAK takes all prices for each week before departure over the last year for round-trip flights from Washington, D.C. Dulles Intl Airport to St. Louis, removes the top 0.1% to account for outliers, and then takes the average of all the values for each week.
To get a below average price on the flight from Washington, D.C. Dulles Intl Airport to St. Louis, you should book around 3 weeks before departure. For the absolute cheapest price, our data suggests you should book 24 weeks before departure.

Good to know

Low season

December

High season

August

Cheapest flight

$55
Best time to beat the crowds but there is an average 15% increase in price.
Most popular time to fly and prices are also 6% lower on average.
Flight from Washington Dulles Airport to St. Louis

When to book flights from Dulles Intl to St. Louis

Are your dates flexible? Find out the best times to travel from Dulles Intl to St. Louis 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 Washington Dulles Airport to St. Louis flights

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

    In the last 3 days, the lowest price for a flight from Washington, D.C. Dulles Intl Airport to St. Louis was $55 for a one-way ticket and $118 for a round-trip.

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

    No, a passport isn't needed to fly from Washington Dulles Airport to St. Louis. However, local authorities might ask for an official ID.

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

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

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

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

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

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

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

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

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

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

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

    The two airlines most popular with KAYAK users for flights from Washington, D.C. to St. Louis are Delta and United Airlines. With an average price for the route of $303 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 $497 and an overall rating of 7.4.

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

    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 Washington Dulles Airport to St. Louis.

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

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to St. Louis from Washington Dulles Airport 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 Washington Dulles Airport to St. Louis?

    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 St. Louis with an airline and back to Washington Dulles Airport with another airline. Booking your flights between Washington Dulles Airport and STL 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 Washington Dulles Airport to St. Louis?

    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 St. Louis from Washington Dulles Airport up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

See more FAQs

KAYAK’s top tips for finding a cheap flight from Washington, D.C. Dulles Intl Airport to St. Louis

  • Looking for a cheap flight? 25% of our users found flights on this route for $216 or less one-way and $418 or less round-trip.

Prefer to fly direct from Washington Dulles Airport to St. Louis?

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

Direct departures

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

Monday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Tuesday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Wednesday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Thursday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Friday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Saturday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Sunday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

See more direct flights

Direct returns

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

Monday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Tuesday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Wednesday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Thursday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Friday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Saturday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

Sunday

Avianca, Brussels Airlines, Copa Airlines, +2 more

Avianca, Brussels Airlines, +3 more

See more direct flights
See more direct flights

Top 3 airlines serving from Dulles Intl to St. Louis

 
See real verified KAYAK customer reviews for airlines flying from Washington, D.C. to St. Louis. 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 Dulles Intl to St. Louis? 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 8456 reviews
7.9Entertainment
8.5Crew
8.2Boarding
7.3Food
8.0Comfort
Airline reviews

Great service. Great staff. Boarding was a little slow, but I think there was a service dog slowing things down.

10.0 ExcellentD, Jan 2025ABE - ATL
Read more Delta reviews

Great service. Great staff. Boarding was a little slow, but I think there was a service dog slowing things down.

Flight left early and arrived early. the whole trip was excellent.

Seats were really tight and the seat belts did not give enough slack.

I like in St George and prefer to fly out of CDC than SGU. Hopefully, they will continue the flights out of Cedar

Broken jer bridge. Poor communication about it. Lost 2 of 4 luggage pieces

Overall, it was okay. Seat was a little cramped. Would’ve liked more substantial snacks or opportunity to buy some.

Newer plane, relatively easy boarding, not a full flight and was told that we could not be moved up because of weight and balance issues. Otherwise, a very good experience.

Other then mechanical/ computer problem and 3.5 hours flight delay the flight was great. I guess that what happened when you fly an old airplane now a day.

I was with one of the last zones to board. It was kind of annoying to finally get called to board and my whole section was already on the plane. Clearly they boarded with previous zones. So by the time I got on board, there were no spaces for my luggage above my head. I had to put my luggage 4+ rows behind me, which meant that I had to wait even longer to get off the plane, since I had to wait for those rows to clear the aisle before I could retrieve my luggage and exit the plane. This also held up the plane cleaners, as they couldn't service my row until I cleared it, so they were all standing there waiting for me, while I'm standing there waiting for the other passengers to clear the aisle. Anyways, I wasn't in a rush this time, so I just waited, but I could see that being a problem in the future. Now, I could have checked my luggage, of course, but coincidentally, a friend of mine on the same flight got their luggage damaged (wheel completely knocked off) and was told by the Baggage Attendant in the airport that Delta doesn't "cover wheel damage" on luggage. This was disappointing to hear. I'm glad I didn't check mine through. If it were my luggage, I'd be highly frustrated to hear that. It makes me not want to check my luggage in the future.

The dear was very limited in space. I could put my water bottle in seat basket. Also, there was no inflight entertainment in the delta app?

I completely missed my flight because the first leg was longer than planned. I had to sleep overnight in the airport because no accommodation was provided and then sent to Trinidad in the morning with an anticipated 7 hour layover before my flight to Georgetown which was now with Caribbean Airlines. I tried twice with customer service to see if they could put me on an earlier flight which had seats available but was told it wasn’t possible.

Short flight - no food understandable. Flight was delayed for over an hour. Overall, it was good.

First class felt like economy, seats were horrible, food was horrible, staff inattentive

EVen warmer in the plane it think it was 24+ degrees

The flying experience was great. The flight was on time with no boarding issues during a peak travel period. The short cut baggage drop and process was not smooth and efficient at Dulles.

Fast checkin with the self serve terminal, good communication at the boarding gate.

Very friendly staff. The flight was on time. Need a bit heavy covers/blankets. It can get colder with a thin blanket.

The plane was clean. The staff was excellent. The flight attendants were very good. Enjoyable flight. Overall. The seats in the back are too small but, will always be.

This was a 5 hour flight with no entertainment and with a snack being provided (pretzels and fruit bar), which are both high in carbs and sugar. Nuts would have been a better choice.

Never nice, United Express partners always do an amazing job.

First, to be fair, the flight was on time and the trip through the air was relatively smooth. But the flight was full, and they were checking carryons. As this process went on, the crew got increasingly rude and overbearing. During the drink service, a young girl (maybe 9) who had gotten up to use the lavatory got stuck behind the cart. At some point, she started feeling fearful and overwhelmed. Passengers noticed this and asked the crew to let her return to her seat. They refused. Then she started crying, and they still refused to move the cart forward to let her sit. The poor girl was trying to be brave and compose herself. The crew handled the situation terribly and with zero grace or decency. That episode, to me, encapsulates AA’s attitude toward its passengers. Disgraceful. The plane itself was cramped and miserable, as usual. There was zero inflight media or entertainment, other than the lane and borderline inappropriate jokes the steward made during the safety briefing. Then, of course, it took the better part of an hour for the checked bags to show up at the carousel. AA is no better than the el cheapo airlines these days and a far, far cry from its former self.

Customer service for American Airlines first class is at an all time low.

Improvements in communication and empathy are absolutely necessary for American Airlines staff (top down). It’s like they are numb to the needs of their customers.

Very mediocre greeting as we boarded, and the lead flight attendant accent was almost unrecognizable. He joked around a lot, while trying to give the safety demonstration, but did not succeed. My wife’s row was completely missed for beverages and the lead flight attendant didn’t even know that our row was Main cabin and able to have beverages at no charge. We are platinum, 2,000,000 miles on American Airlines and this was not a stellar crew.

No overhead space so all carryons were checked. No internet.

Check bag location is full of rude employees who are unwilling to assist with issues after talking to AA on the phone and relaying messages. The boarding was good. While on the flight it got really hot. Asked flight attendant if there’s a way to drop the temp and make it more comfortable as we are flying from DC to Miami so flying from cold to hot weather. No changes made. Stayed hot and uncomfortable on the plane. When asked again about the AC being down the flight attendant said no the WiFi was down but not the AC. I mentioned it was still hot. No changes.

No food, no entertainment. But the flight was really short so maybe they had to skip drinks. I was able to board early ONLY because I am old and decrepit and they let me pre-board. I RESENT your dumping us into category 9 if we do not pay up. And when I paid for a seat I was STILL given 9. The pre-boarding helps. THIS flight was exceptionally smooth, please congratulate the pilots.

On time (actually a little early). Was a good and short flight!

I had a TERRIBLE experience with the AA crew. I believe it was disability-related. It’s unlikely I will fly AA again.

Great - quick boarding and landed early with an available gate.

Everything you need to know for your flight from Dulles Intl to St. Louis

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