STL - IAD

$61 Find Cheap Flights from St. Louis to Washington Dulles Airport - Compare and Save

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Everything you should know

Cheapest round-trip
$185
Typical prices: $275-$481
Frontier
Sun 10/21Thu 10/25
STL - IAD • 1 stop
Cheapest non-stop
$255
Typical prices: $379-$588
United Airlines
Fri 11/9Wed 11/14
STL - IAD • Non-stop
Nonstop flights
Every day
You can fly direct with United Airlines. Average duration is 2h 12m
Direct flights
+1
Direct flights
+1
When to travel
October
Cheapest • 28% price drop
November
Most popular
Good to know
+1
Good to know
+1
Top layover airports
Atlanta Hartsfield-Jackson (ATL)
Cheapest • Avg $262 (round-trip)
Detroit Metropolitan Wayne County (DTW)
Shortest trip • 4h 37m (one-way)
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We hope you love your trip to Washington, D.C. Dulles Intl Airport!
Flight Deals
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Expert advice
Flight Deals

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

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

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

Wed, Oct 21 - Sun, Oct 25
Frontier Logo
6:35 pm - 12:21 amSTL  Lambert-St Louis-IAD Washington, D.C. Dulles Intl
4h 46m1 stop Atlanta Hartsfield-Jackson
Frontier Logo
11:12 am - 11:13 pmIAD  Washington, D.C. Dulles Intl-STL Lambert-St Louis
13h 01m1 stop Orlando
$185Frontier
Mon, Dec 7 - Thu, Dec 17
Delta Logo
6:05 pm - 11:23 pmSTL  Lambert-St Louis-IAD Washington, D.C. Dulles Intl
4h 18m1 stop Detroit Metropolitan Wayne County
Delta Logo
6:00 am - 9:23 amIAD  Washington, D.C. Dulles Intl-STL Lambert-St Louis
4h 23m1 stop Detroit Metropolitan Wayne County
$237Delta
Thu, Oct 29 - Sat, Oct 31
United Airlines Logo
5:00 am - 11:52 amSTL  Lambert-St Louis-IAD Washington, D.C. Dulles Intl
5h 52m1 stop Chicago O'Hare Intl
United Airlines Logo
8:23 am - 12:12 pmIAD  Washington, D.C. Dulles Intl-STL Lambert-St Louis
4h 49m1 stop Chicago O'Hare Intl
$237United Airlines
Mon, Oct 5 - Wed, Oct 7
United Airlines Logo
3:11 pm - 9:11 pmSTL  Lambert-St Louis-IAD Washington, D.C. Dulles Intl
5h 00m1 stop Chicago O'Hare Intl
United Airlines Logo
8:20 am - 12:13 pmIAD  Washington, D.C. Dulles Intl-STL Lambert-St Louis
4h 53m1 stop Chicago O'Hare Intl
$237United Airlines
Thu, Dec 10 - Sat, Dec 12
Delta Logo
6:00 am - 11:39 amSTL  Lambert-St Louis-IAD Washington, D.C. Dulles Intl
4h 39m1 stop Atlanta Hartsfield-Jackson
Delta Logo
6:00 am - 9:23 amIAD  Washington, D.C. Dulles Intl-STL Lambert-St Louis
4h 23m1 stop Detroit Metropolitan Wayne County
$237Delta
Fri, Oct 2 - Wed, Oct 7
Frontier Logo
5:19 pm - 12:10 amSTL  Lambert-St Louis-IAD Washington, D.C. Dulles Intl
29h 51m2 stops Orlando Atlanta Hartsfield-Jackson
Frontier Logo
7:50 am - 1:10 pmIAD  Washington, D.C. Dulles Intl-STL Lambert-St Louis
6h 20m1 stop Atlanta Hartsfield-Jackson
$238Frontier
Tue, Oct 13 - Thu, Oct 15
American Airlines Logo
3:30 pm - 8:46 pmSTL  Lambert-St Louis-IAD Washington, D.C. Dulles Intl
4h 16m1 stop Charlotte Douglas
American Airlines Logo
5:01 am - 8:37 amIAD  Washington, D.C. Dulles Intl-STL Lambert-St Louis
4h 36m1 stop Charlotte Douglas
$275American Airlines
Sat, Nov 14 - Thu, Nov 19
American Airlines Logo
6:00 am - 11:17 amSTL  Lambert-St Louis-IAD Washington, D.C. Dulles Intl
4h 17m1 stop Charlotte Douglas
American Airlines Logo
1:24 pm - 7:08 pmIAD  Washington, D.C. Dulles Intl-STL Lambert-St Louis
6h 44m1 stop Charlotte Douglas
$275American Airlines
Fri, Nov 20 - Mon, Nov 30
Multiple Airlines Logo
6:35 pm - 3:03 pmSTL  Lambert-St Louis-IAD Washington, D.C. Dulles Intl
19h 28m1 stop Atlanta Hartsfield-Jackson
Multiple Airlines Logo
6:36 pm - 12:41 amIAD  Washington, D.C. Dulles Intl-STL Lambert-St Louis
31h 05m2 stops Blountville Tri Cities TN/VA Orlando
$286Multiple Airlines
Thu, Oct 1 - Thu, Oct 8
Multiple Airlines Logo
6:39 pm - 5:56 pmSTL  Lambert-St Louis-IAD Washington, D.C. Dulles Intl
22h 17m2 stops Orlando Blountville Tri Cities TN/VA
Multiple Airlines Logo
9:06 pm - 5:40 pmIAD  Washington, D.C. Dulles Intl-STL Lambert-St Louis
21h 34m1 stop Atlanta Hartsfield-Jackson
$303Multiple Airlines
Booking Insights

Price, demand and travel trends for St. Louis to Washington, D.C. Dulles Intl Airport flights

Use KAYAK data on prices, travel dates, airlines and seasonal trends to compare options and book flights from St. Louis to Washington, D.C. Dulles Intl Airport with more confidence.

How much is a round-trip flight from St. Louis to Washington, D.C. Dulles Intl Airport?

Round-trip flights from St. Louis to Washington, D.C. Dulles Intl Airport start at $185. Prices are below average for this route right now, with typical round-trip fares ranging from $275 to $481. The lowest price found in the past 5 days was $185 on Frontier.

What's the cheapest day of the week to fly from St. Louis to Washington, D.C. Dulles Intl Airport?

Thursday is the cheapest day of the week to fly from St. Louis to Washington, D.C. Dulles Intl Airport, it is 37% cheaper than the average day. Tuesday is the most expensive day with flight prices 27% higher than average. Based on deals found by KAYAK users in the last 12 months.

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

  • October is the cheapest month to fly from St. Louis to Washington, D.C. Dulles Intl Airport at $271 round-trip.
  • August ($567) and June ($468) are the most expensive months.
  • The price difference between flying in the cheapest and most expensive months is 109% on average.
This is based on KAYAK aggregated and averaged internal data over the past 12 months.

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Expert advice

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

 
KAYAK teamed up with top travel experts to share the best tips for your journey.
Our travel experts
Jessica Macdonald

Jessica Macdonald

Expert on Lufthansa

Currently based in Scotland after living in South Africa and the United States, Jessica has been writing travel and aviation content for more than 10 years. She regularly contributes to Travel + Leisure and TripSavvy, and has had work published by Condé Nast Traveller and The Independent. She has traveled to more than 50 countries across six continents.

Read more
Stefanie Waldek

Stefanie Waldek

Expert on United Airlines and IAD

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
Yulia Denisyuk

Yulia Denisyuk

Expert on STL

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

Key details for St. Louis to Washington, D.C. Dulles Intl Airport flights

Low season

August

Cheapest flight

$61
Best time to beat the crowds but there is an average 52% increase in price.
Most popular time to fly with an average 3% increase in price.
Flight from St. Louis to Washington, D.C. Dulles Intl 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

Your St. Louis to Washington, D.C. Dulles Intl Airport flight questions, answered

Find helpful route details based on KAYAK data, including flight times, airports, airlines and booking questions.

  • Which airlines offer extra legroom and free seat selection on St. Louis to Washington, D.C. Dulles Intl Airport flights?

    Among airlines operating St. Louis to Washington, D.C. Dulles Intl Airport flights:

    • United Airlines: offers extra legroom; offers free seat selection

    Extra legroom and free seat selection availability depends on fare class and route.

  • What airlines are available from St. Louis to Washington, D.C. Dulles Intl Airport?

    Only United Airlines operates flights between St. Louis and Washington, D.C. Dulles Intl Airport.

  • Which airports can I use when flying from St. Louis to Washington, D.C. Dulles Intl Airport?

    Flights from St. Louis to Washington, D.C. Dulles Intl Airport usually depart from Lambert-St Louis (STL) and arrive at Washington, D.C. Dulles Intl (IAD).

  • Which airlines include bags at no extra cost on St. Louis to Washington, D.C. Dulles Intl Airport flights?

    Here are some options for this route, based on selected ticket types and cabin classes:

    • United Airlines: a cabin bag and a checked bag in Economy Class
    • JetBlue: a cabin bag in Economy Class class

    Bag allowance can vary by ticket type, cabin class, route and airline, so travelers should check the fare details before booking.

  • What cabin classes can I book on flights from St. Louis to Washington, D.C. Dulles Intl Airport?

    Two cabin classes are available on flights from St. Louis to Washington, D.C. Dulles Intl Airport:

    • Economy Class
    • First Class

  • How much can I save by taking a layover when flying from St. Louis to Washington, D.C. Dulles Intl Airport?

    On this route, layover flights are cheaper than nonstop options on average. Layover fares average $262 round-trip via Atlanta Hartsfield-Jackson (ATL), compared to $465 for nonstop.

  • What is the standard checked-bag allowance on flights from St. Louis to Washington, D.C. Dulles Intl Airport?

    There is no standard. Checked-bag policies vary by airline on this route. Most carriers charge $40–$80 for the first checked bag in economy. Premium fares and elite-status bookings typically include a free checked bag.

  • Which aircraft model is used most often on flights from St. Louis to Washington, D.C. Dulles Intl Airport?

    The Canadair (Bombardier) Regional Jet CRJ-550 family is used most often on this route, operated mainly by United Airlines. Other aircraft seen on the route include Embraer 175 (Enhanced Winglets) variants.

  • Which airports do connecting flights from St. Louis to Washington, D.C. Dulles Intl Airport pass through?

    One-stop flights from St. Louis to Washington, D.C. Dulles Intl Airport most commonly connect through:

    • Atlanta Hartsfield-Jackson (ATL) - 62% of one-stop connections
    • Charlotte Douglas (CLT) - 20% of one-stop connections
    • Chicago O'Hare Intl (ORD) - 10% of one-stop connections
    • Detroit Metropolitan Wayne County (DTW) - 7% of one-stop connections

    Atlanta Hartsfield-Jackson (ATL) handles the largest share of one-stop connections on this route.

  • Can I save money by using flexible dates for flights from St. Louis to Washington, D.C. Dulles Intl Airport?

    Yes. Being flexible with your travel dates can save you up to 50% on the St. Louis to Washington, D.C. Dulles Intl Airport route. Thursday is the cheapest departure day at $239 round-trip on average, while Tuesday is the most expensive at $476, a difference of $237. KAYAK's flexible dates feature shows options up to 3 days before and after your selected dates, making it easier to compare nearby fares.

  • How are flight departures from St. Louis to Washington, D.C. Dulles Intl Airport spread across the day?

    Morning is the busiest departure period on St. Louis to Washington, D.C. Dulles Intl Airport flights, with 50% of flights leaving in that window. Afternoon departures account for 50%, evening flights for 0%, and night flights for 0%.

  • What popular places can I visit in Washington, D.C. Dulles Intl Airport?

    Some of the most popular sights in Washington, D.C. Dulles Intl Airport are Walter E. Washington Convention Center, National Mall and Capital One Arena. These are among the most viewed places in Washington, D.C. Dulles Intl Airport on KAYAK.

  • What are the earliest and latest flights from St. Louis to Washington, D.C. Dulles Intl Airport?

    These are the earliest and latest flight times available from St. Louis to Washington, D.C. Dulles Intl Airport:

    • Earliest: departs at 8:00 am and lands at 10:12 am
    • Latest: departs at 6:00 pm and lands at 8:12 pm.

    The flight takes about 2h 12m.

  • How long is a flight from St. Louis to Washington, D.C. Dulles Intl Airport?

    A nonstop flight from St. Louis to Washington, D.C. Dulles Intl Airport takes 2h 12m, covering 694 miles.

  • Do I need a passport to fly from St. Louis to Washington, D.C. Dulles Intl Airport?

    No, a passport is not required for this domestic route, but you will need a real ID-compliant driver's license, a state ID, or another TSA-accepted form of identification.

  • How are flight prices from St. Louis to Washington, D.C. Dulles Intl Airport looking right now?

    One-way fares from St. Louis to Washington, D.C. Dulles Intl Airport are currently lower than usual. Average one-way flight prices are about $124, which is 45% below the typical average for this route.

  • How much time can I save by choosing a different layover airport from St. Louis to Washington, D.C. Dulles Intl Airport?

    Flying via Detroit Metropolitan Wayne County (DTW) gives the shortest average 1-stop total travel time at 4h 37m, compared with 4h 49m via Chicago O'Hare Intl (ORD) and 4h 53m via Charlotte Douglas (CLT).

  • What is the time difference between St. Louis and Washington, D.C. Dulles Intl Airport?

    Washington, D.C. Dulles Intl Airport is 1 hour ahead of St. Louis (Eastern Time vs Central Time). Plan for the time shift when scheduling connections or first-day activities.

  • What car rental options are available at Washington, D.C. Dulles Intl Airport (IAD)?

    Washington, D.C. Dulles Intl Airport (IAD) hosts 5 major car rental companies, with daily rates starting from around $24 for economy cars. Top options include:
    • Dollar
    • Budget
    • Hertz
    • Sixt
    • Thrifty

  • How much should I expect to pay for a St. Louis to Washington, D.C. Dulles Intl Airport flight?

    Round-trip flights from St. Louis to Washington, D.C. Dulles Intl Airport range from $275 to $481, with an average of $374 over the past 12 months. Anything below $275 counts as a good deal.

  • Which airlines offer Wi-Fi on St. Louis to Washington, D.C. Dulles Intl Airport flights?

    JetBlue is the only airline on the St. Louis to Washington, D.C. Dulles Intl Airport route offering in-flight Wi-Fi. Pricing depends on fare class.

Your guide to booking St. Louis to Washington, D.C. Dulles Intl Airport flights

Get tips on when to book, when to fly and what to know before your trip.
  • If your dates can be flexible, aim for a Thursday departure instead of Tuesday. On this route, Thursday flights average $239 - about $237 less than Tuesday (50% savings) based on the last 12 months.
  • If you can choose when to travel, plan your St. Louis to Washington, D.C. Dulles Intl Airport trip for October. Fares historically average $271 round-trip in that month - typically $296 less than the most expensive month, which is August (based on the last 12 months).
  • If you have the time, taking a 1-stop flight through Atlanta Hartsfield-Jackson Airport (ATL) can be cheaper than flying direct. The cheapest layover option averages $262 round-trip on this route - about $203 less than direct flights (based on the last 12 months).

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

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

Direct departures

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

Monday

United Airlines

United Airlines

Tuesday

United Airlines

United Airlines

Wednesday

United Airlines

United Airlines

Thursday

United Airlines

United Airlines

Friday

United Airlines

United Airlines

Saturday

United Airlines

United Airlines

Sunday

United Airlines

United Airlines

See more direct flights

Direct returns

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

Monday

United Airlines

United Airlines

Tuesday

United Airlines

United Airlines

Wednesday

United Airlines

United Airlines

Thursday

United Airlines

United Airlines

Friday

United Airlines

United Airlines

Saturday

United Airlines

United Airlines

Sunday

United Airlines

United Airlines

See more direct flights

More options for your flight from St. Louis to Dulles Intl

Complete your trip to Washington, D.C. with a hotel stay or car rental

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