IAD - STL

$103 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 10/30. 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
1 adult, Economy

KAYAK searches hundreds of travel sites at once for deals on flights to St. Louis

 
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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Flights Deals

Cheap Flights 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.
Discover the best prices for you by selecting your travel dates on KAYAK.

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

Sat, Aug 16 - Mon, Aug 18
Frontier Logo
1:37 pm - 11:47 pmIAD-STL
11h 10m1 stop
Frontier Logo
2:37 pm - 6:34 amSTL-IAD
14h 57m1 stop
$208Frontier
Find Deal
Wed, Aug 13 - Sun, Aug 17
Frontier Logo
7:30 am - 1:42 pmIAD-STL
31h 12m1 stop
Frontier Logo
2:36 pm - 12:19 amSTL-IAD
8h 43m1 stop
$209Frontier
Find Deal
Wed, Aug 13 - Sat, Aug 16
Frontier Logo
7:30 am - 1:42 pmIAD-STL
31h 12m1 stop
Frontier Logo
2:52 pm - 11:26 pmSTL-IAD
7h 34m1 stop
$215Frontier
Find Deal
Wed, Aug 27 - Wed, Sep 3
United Airlines Logo
8:40 am - 10:02 amIAD-STL
2h 22mnonstop
United Airlines Logo
8:15 am - 11:25 amSTL-IAD
2h 10mnonstop
$217United Airlines
Find Deal
Wed, Aug 27 - Wed, Sep 3
United Airlines Logo
8:40 am - 10:02 amIAD-STL
2h 22mnonstop
United Airlines Logo
9:17 am - 2:37 pmSTL-IAD
4h 20m1 stop
$227United Airlines
Find Deal
Wed, Aug 27 - Wed, Sep 3
Delta Logo
7:22 am - 12:31 pmIAD-STL
6h 09m1 stop
Delta Logo
6:00 am - 11:23 amSTL-IAD
4h 23m1 stop
$237Delta
Find Deal
Sat, Aug 23 - Mon, Aug 25
Delta Logo
12:39 pm - 7:07 pmIAD-STL
7h 28m1 stop
Delta Logo
3:42 pm - 11:21 pmSTL-IAD
6h 39m1 stop
$254Delta
Find Deal
Thu, Aug 28 - Sat, Aug 30
American Airlines Logo
6:34 am - 12:11 pmIAD-STL
6h 37m1 stop
American Airlines Logo
5:27 am - 12:48 pmSTL-IAD
6h 21m1 stop
$271American Airlines
Find Deal
Wed, Sep 10 - Tue, Sep 16
American Airlines Logo
11:18 am - 9:53 pmIAD-STL
11h 35m2 stops
American Airlines Logo
8:17 am - 1:51 pmSTL-IAD
4h 34m1 stop
$299American Airlines
Find Deal
Thu, Aug 14 - Sun, Aug 17
 Logo
11:04 am - 6:41 pmIAD-STL
8h 37m2 stops
 Logo
10:37 am - 2:23 pmSTL-IAD
26h 46m3 stops
Expert advice

Expert advice for your flight from Dulles Intl to St. Louis

 
Snippets provided in this section are AI-generated based on a summarization of KAYAK-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
KAYAK teamed up with top travel experts to share the best tips for your journey.
Airports
IAD

For quick navigation at Dulles, use the AeroTrain for Concourses A, B, and C. Mobile lounges connect to Concourse D.

Read more about IADby Stefanie Waldek
STL

Use MetroLink for easy access from STL to downtown St. Louis. The Red Line connects the airport to key city areas.

Read more about STLby Yulia Denisyuk
Our travel experts
Yulia Denisyuk

Yulia Denisyuk

Expert on STL

Yulia Denisyuk

Yulia Denisyuk

Yulia is a freelance journalist who’s dispatched from 90+ countries. Her work focuses on cultures, adventure trips and air travel, appearing in NatGeo, NYT, CNTraveler, and more. For past assignments, she’s stayed with nomads in Mongolia and learned the art of Imigongo in Rwanda. She’s based in Chicago; in winter she often questions that decision.

Read more
Stefanie Waldek

Stefanie Waldek

Expert on IAD

Stefanie Waldek

Stefanie Waldek

Stefanie Waldek is a freelance space, travel, and design writer based in Saratoga Springs, NY. Her words have appeared in Space.com, Travel + Leisure, Condé Nast Traveler, Architectural Digest, and House Beautiful, among other publications. An expert in aviation and expedition cruising, Stefanie is frequently up in the air or on the sea, likely en route to Antarctica or the Arctic.

Read more
Booking Insights

KAYAK's insights & trends for Dulles Intl to St. Louis flights

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, Wednesday 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 Monday 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 July, where tickets cost $299 (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 $472 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.

Yes, flying with a layover may cost you more time, but you can also save money on the route, with a 1 stop layover the cheapest option at $585 on average.

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 4 weeks before departure, which saves you about 46% compared to booking last minute. For the absolute cheapest price, our data suggests you should book 19 weeks before departure.

Good to know

Low seasonJune
Cheapest flight$103
Best time to beat the crowds with an average 4% drop in price.
Most popular time to fly with an average 1% increase in price.
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 $103 for a one-way ticket and $208 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 $295 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 $477 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.

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 $244 or less one-way and $472 or less round-trip.

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

 
Direct data is based off flight results for the next 60 days. Find direct flights from all airlines flying direct from Washington, D.C. Dulles Intl to Lambert-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

Reviews of the 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 7980 reviews
7.9Comfort
8.2Boarding
8.5Crew
7.9Entertainment
7.3Food
Airline reviews

Delayed and took off even later than the scheduled delay time

8.0 ExcellentAnonymous, Jul 2025DTW - SEA
Read more Delta reviews

Delayed and took off even later than the scheduled delay time

For a 69 year old with health problems I had the worse experience, no wheelchair when I entered a lady told me to sit and wait while a gentleman told me I had to walk to the Delta station, which I did. I had a carry on and a bag, and I was traveling with my service dog, which was on his carrier and the lady charged me for my carry on luggage, beside all the waiting cause of the delay, I had to walk to get my luggage cause no wheelchair showed up, I am so disappointed. I will get in touch with the company. I got home at 3:00 am, not good for my health situation.

Great experience on Delta. Staff from baggage check to flight attendants were very courteous and professional. My only issue was a personal preference for pretzels instead of the chips and cookies that were offered.

There was no problems, just a little uncomfortable with seats that do not lay back a little

Always good but we must do something about people in rows ahead of you that don't put their seats back up when they are suppose to. And It's rough to not be able to even lean over to get something out of my purse.

Flight was delayed, 30+ bags had to be gate checked. Crew were very friendly!

Everything was good until we were boarding our connection flight in Atlanta, we were told to gate check our carry-on, but when we got inside the plane, there was plenty of room in the overhead.

Did not know my son and I had different seating arrangements. He was fine, but it was disappointing.

Flight was canceled, and no effort was made to help with rebooking, no hotel vouchers, no car transportation and minimal food voucher and most places for food were closed by the time the voucher was given. Waited for 3 hours for bags. Simply the worst travel experience I have ever had

Food was surprisingly good but the WiFi was not great

Was on time until within 1 hour of flight-how does that happen? Staff very friendly.

Weather delay in Chicago?. No sense of urgency to make connection in Chicago for our connecting flight that wasn't delayed. Connection was missed.

Our flight was understandably diverted to a small regional airport in Laramie, Wyoming due to weather conditions, which I fully recognize and appreciate. However, the low rating stems from the experience that followed: passengers remained on board for over an hour without the option to deplane and stretch, despite the aircraft being stationary. Although the pilot opened the cabin door, only he was permitted to exit. Meanwhile, passengers grew increasingly uncomfortable as warm summer air entered the cabin through the open door, and being in the second row meant we were impacted immediately. While the flight attendants made efforts to keep everyone at ease, I believe allowing passengers to deplane briefly, given the extended delay, would have significantly improved the overall experience.

I liked the choice of lemon ginger tea. I think stewardesses can be more considerate of older people needs.

We were given vouchers we couldn’t use with a 5.5 hour delay

I fly UAL 7-8 times per year. This flight was not up to snuff because it boarded very late "due to unexpected delays in restocking the plane" and yet Flight Aware showed the plane had landed some 10 hours earlier--so I think they could have planned accordingly. The FA's were nice but harried. The video system had to be rebooted 3-4 times. The food service was rather abrupt; they forgot my row and when I asked for my meal, they brought it with some impatience. Overall, the flight was fine, but the little details made it feel somewhat mundane and hurried.

I didn’t get on plane. Passport being processed by consulate with visa application. Tried to cancel through underpricer after purchasing cacelling for any reason. No dice, they are thieves.

When I booked it on Kayak it aaid that I wasn't allowed hamd luggage. I called United Airlines and it took them 6 minutes to figure out if I was allowed free hand luggage. Surely something that simple they should be able to tell me instantly.

We were delayed in Toronto on the tarmac for THREE hours with no clear indication as to why except that it was not a safety hazard. Pilot did apologize more than once but even he was unable to explain why exactly we were delayed. I overheard the stewards saying that the captain was very frustrated with the situation as well because he was not able to explain why except it had something to do with water supply or system on the aircraft and now we needed to wait for an engineer to approve the aircraft for flight. It was very frustrating and distressing as a passenger and we should have been given complimentary meals at the very least.

Flight was cramped with every seat taken. The food was fine, nothing crazy to write home about. The plane felt dated and needing some TLC, the button for the window shade didn't work and there were no AC outlets to use. When communicating with staff all except one nice lady never seemed happy to help me almost like I was bothering them when asked for things like a glass of water or a snack. The flight was overall fine. It did what was needed which is get me from point A to point B. But it certainly was not special. I don't expect much in economy but I believe economy on a host of other airlines is more memorable and better experience.

They are still charging me after taking 466 and 833 for round trip from AR to to Bradley airport from 19 to 21. Then poor experience. Am hurt and I will say it on social media. Please stay away from this airline. I see in my bank account they are still taking 644. Am trying to stop it. I used to fly United airlines and I suggest that if you don't want extra charges and good service you go back there. American airlines delayed my flight again and I was late for my meeting, no recompensation but charging me over and over.

They changed our Gate 5 times, and concourse twice. Changed our seats twice.

Pitch was very small. Knees were on the seat back in front of me.

Wonderful as usual except for other guests that were unruly and not kept in check by the Crew.

The flight was initially delayed, then cancelled. American Airlines says the cancellation was weather related, though the actual weather was not bad in both Washington and Providence and between. There were very few cancellations that day. In fact, AA2120 from Washington, DC to Boston flew with a minor delay at about the same time. So, the weather somehow affected only this particular flight AA5230. The next available flight was the following morning. The American Airlines refused to reimburse accommodation (hotel at DCA)

Fine. On time, cabin service was fine, bag arrived. All good. Flying into DCA so did not collide with any helicopters, which is also good. Horrid incident that could have and should have been prevented.

Good experience but the snacks are not gluten free, so I cannot eat them.

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.

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

Information on your arrival and departure airports

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