IAD - STL

$75 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 4/2. 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 Dulles Intl 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 Dulles Intl 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
5:54 pm - 11:46 pmIAD-STL
6h 52m1 stop
4:57 pm - 5:02 pmSTL-IAD
23h 05m1 stop
$150Frontier
Find Deal
Tue, Apr 1 - Tue, Apr 8
5:54 pm - 11:49 pmIAD-STL
6h 55m1 stop
5:24 pm - 3:10 pmSTL-IAD
20h 46m1 stop
$160Frontier
Find Deal
Tue, Mar 25 - Thu, Mar 27
5:54 pm - 11:46 pmIAD-STL
6h 52m1 stop
4:57 pm - 10:55 amSTL-IAD
16h 58m1 stop
$170Frontier
Find Deal
Tue, Apr 1 - Sat, Apr 5
5:54 pm - 9:36 amIAD-STL
16h 42m1 stop
5:24 pm - 4:54 pmSTL-IAD
22h 30m1 stop
$180Frontier
Find Deal
Sun, Mar 16 - Tue, Mar 18
8:35 am - 9:58 amIAD-STL
2h 23mnonstop
3:40 pm - 9:01 pmSTL-IAD
4h 21m1 stop
$187United Airlines
Find Deal
Tue, Apr 29 - Wed, Apr 30
8:35 am - 12:20 pmIAD-STL
4h 45m1 stop
3:40 pm - 9:01 pmSTL-IAD
4h 21m1 stop
$197United Airlines
Find Deal
Tue, Apr 29 - Wed, Apr 30
6:00 am - 9:36 amIAD-STL
4h 36m1 stop
6:39 am - 11:31 amSTL-IAD
3h 52m1 stop
$223Delta
Find Deal
Thu, Apr 3 - Sun, Apr 6
7:35 am - 11:45 amIAD-STL
5h 10m1 stop
6:00 am - 11:23 amSTL-IAD
4h 23m1 stop
$228Delta
Find Deal
Sun, Apr 20 - Thu, Apr 24
9:10 am - 12:53 pmIAD-STL
4h 43m1 stop
1:48 pm - 7:41 pmSTL-IAD
4h 53m1 stop
$267American Airlines
Find Deal
Wed, Apr 9 - Tue, Apr 22
5:02 am - 8:56 amIAD-STL
4h 54m1 stop
9:36 am - 4:56 pmSTL-IAD
6h 20m1 stop
$325American Airlines
Find Deal
Thu, May 8 - Sun, May 11

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 Friday 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 April, where tickets cost $397 (return) on average. On the other hand, the most expensive months are December and May, where the average cost of round-trip tickets is $499 and $481 respectively.

Can I save money by flying with a layover from Washington, D.C. Dulles Intl Airport to St. Louis?

The average round-trip price for all non-stop flights, flights with one layover, and flights with two layovers for the route found by users searching on KAYAK in the last 2 weeks.
No, with an average price for the route of $390, prices are generally cheapest when you fly direct.

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 18 weeks before departure.

Good to know

Low season

December

High season

March

Cheapest flight

$75
Best time to beat the crowds but there is an average 15% increase in price.
Most popular time to fly and prices are also 2% 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 $75 for a one-way ticket and $150 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 $308 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 $498 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 $353 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 8070 reviews
8.5Crew
8.0Comfort
7.3Food
7.9Entertainment
8.2Boarding
Airline reviews

Seats are much much more comfortable than United, which is what I usually fly

10.0 ExcellentEmily, Feb 2025BOS - SFO
Read more Delta reviews

Seats are much much more comfortable than United, which is what I usually fly

Zero updates from the pilots for 30 minutes in the tarmac

Boarding is, as it always is… horrible. Gate lice. Slow moving zones. Too many people with carry ons

I loved having a most black flight crew during Black History Month; rather by design or accident I appreciated the representation. ❤️

This was the second flight this week with flight attendant Marcus I’m not sure if his last name is Lane or Lang but this guy is awesome. He funny, attentive and his service is 5 stars. Marcus makes business travel more enjoyable !

Although the flight left late, we arrived early. It was one of the quickest boarding and off boarding experiences I’ve had. It was kind of annoying the only drinks they had were water, coffee, and tea. The flight was very smooth, temperature was just right, and flight attendants were friendly.

Lower number on this flight so spaced out passengers. Able to enjoy more room to relax during flight. It was lovely.

Kind staff. Snacks are small but that’s the new normal.

The young man who was our flight attendant in first class was lazy and did not do his job well at all. Never offered drinks upon boarding - actually I take that back... said "are you okay with water" as if I do not want to get you anything else, only passed the snacks around once, got my drink order wrong and then never offered a second round of drinks. He was the worst I have ever seen on Delta and we fly a lot.

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

Delays took 2hours and thirty minutes making me miss my connecting flight and make me sit in the Chicago airport for 9 hours

The flight was heavily booked so boarding was a lengthy process. The FA’s were rather abrupt during this process but became more gracious as the flight went on. Breakfast (puffed pastry and chewy sausage) was pretty horrible but there was fruit and yogurt which they didn’t mess up. Overall it was fine.

Liked nothing. As per previous segment it was delay delay delay.

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.

I didn’t like anything, being platinum pro get you absolutely nowhere and does not increase the customer service treatment whatsoever anymore. My flight was canceled and they put me on a flight eight hours later that would’ve got me back in the middle of the night. They could’ve easily move me up to an hour Prior on an earlier flight. My second flight was unreasonable to take, the third flight was also canceled due to mechanical issues like the first flight. I don’t know what’s going on with American, but they are falling apart, after seven flight changes I finally got home, Unreasonable.

Awkward carry on process. Forced to check all carry on. No overhead space of worthiness. Left delayed, but made up the time. Crew was amicable.

Standard. No different than a discount carrier on a short trip.

Everything was great. Boarding, early departure, early arrival, and deplaning were smooth. Smooth flight.

I blame kayak for my last trip to dca. Kayak cancelled my direct flight and put on a one stop flight and made lost whole day from my vacation and had not even refunded my ticket.

I flew out of Reagan National. My flight was delayed, delayed, delayed, and then canceled ...THREE TIMES over TWO DAYS. Staff were seemingly not empowered to provide information on why the flights were screwed up. A real nightmare.

I had two wonderful flights - very relaxing and got me there early!

Cancelled and rebooked twice in one day with a drop in seat class. Not good at all.

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.

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

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