Cheap Flights from St. Louis (XLS) to Washington (IAD)

Popular airlines from St. Louis (XLS) to Washington Dulles Intl. Airport (IAD)

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Frequently asked questions

How much does a flight from St. Louis (XLS) to Washington Dulles Intl. Airport (IAD) cost?
Lock in a cheap one-way flight or cheap return flight from St. Louis (XLS) to Washington Dulles Intl. Airport (IAD) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight deals on this route.
What is the cheapest month to fly from St. Louis (XLS) to Washington Dulles Intl. Airport (IAD)?
The cheapest month to fly from XLS to IAD is , when there's less demand. Off-peak season is often when airlines offer lower prices between these airports.
What is the cheapest airline that flies from St. Louis (XLS) to Washington Dulles Intl. Airport (IAD)?
Expedia's filter tool lets you easily compare different airlines, departure times and fares all in one place. Select your preferences, then sort by "Price (lowest to highest)" to find the carrier with the cheapest XLS to IAD flight.
How many flights per day from St. Louis (XLS) to Washington Dulles Intl. Airport (IAD)?
Direct flights from St. Louis (XLS) to Washington Dulles Intl. Airport (IAD) aren't available daily, so you'll need to take a flight with a layover. Explore your options with Expedia's filters. Enter your travel dates and select either "1 Stop" or "2+ Stops."
What day of the week has the most flights from XLS to IAD?
Typically you'll find the most flight options available on a Friday. Tuesdays tend to be the quietest.* But this can change depending on the airline, time of year and other factors.*Busiest/quietest day to travel is based on Expedia flight demand through January to December 2024.
What is the best time to fly from St. Louis (XLS) to Washington Dulles Intl. Airport (IAD)?
To reach Washington Dulles Intl. Airport (IAD) without delays, pick a flight that leaves from St. Louis (XLS) before 3 PM. The likelihood of cancellations is 22% higher, on average, for departures after this hour.**Most reliable time of the day and month to travel recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.
Is it cheaper to buy a plane ticket from St. Louis (XLS) to Washington Dulles Intl. Airport (IAD) last-minute?
Waiting until just before your departure to book a ticket from XLS to IAD often results in higher prices. While you may find some last-minute discounts, they're not always guaranteed. Allow some flexibility in your schedule to boost your chances of scoring a bargain.
Is it cheaper to book a XLS to IAD flight and hotel package?
Booking a XLS to IAD flight and hotel package tends to be cheaper than booking separately. With Expedia, you can enjoy the convenience of organizing your travels in one place. Choose from our impressive range of hotels and then add flights, car rentals and activities to your booking. Bundle everything together, and you could save hundreds of dollars.
Can I cancel or change the date of my flight from St. Louis (XLS) to Washington Dulles Intl. Airport (IAD)?
If you reserved your XLS to IAD flight within the last 24 hours, you may be able to modify or cancel it without fees. Depending on the airline and the type of fare you have, additional charges may apply for changes after that time. Airline policies and contact information can be found in your itinerary or confirmation email. Or, visit our Customer Service portal for further details.

Travel information

Travel information

Origin airport
St. Louis
Destination airport
Washington Dulles Intl.
Distance
3977 mi

Book with confidence

Book with confidence

St. Louis to Washington Flights

The cheapest times to fly from St. Louis to Washington

On average, Thursday can be the cheapest time to fly, according to data from the Airlines Reporting Corporation (ARC), one of the world's biggest databases for global airline sales. The data reveals that you could save up to 16% by flying on a Thursday—the cheapest day to travel on average—instead of a Sunday—the most expensive. Some of the most affordable flights from St. Louis to Washington are during the month of . You can find some of the cheapest flights from St. Louis to Washington with Expedia's search tool and vast selection of airlines.

 

The best time to book a flight from St. Louis to Washington

Sunday is one of the best days to book for cheap flights from St. Louis to Washington: Tickets reserved on a Sunday cost between 6% and 13% less than those reserved on a Friday, according to ARC data. The data also suggests booking early can also lead to cheaper airfares. You could save 24% by buying your tickets for domestic flights at least a month in advance and 10% by booking international flights 2 months in advance.

 

How to find cheap round-trip tickets from St. Louis to Washington

Being flexible with your dates and using Expedia's Price Drop Protection and Price Tracking features are some of the best ways of finding a cheap ticket from St. Louis to Washington in 2025. You can also book with separate airlines for your outbound and return journeys, from one-way. Expedia also offers Price Drop Protection, so if the cost of your airfare goes down after booking, you'll receive a credit for the difference*. This is available for a small fee, and is free to One Key Gold and Platinum tier members.

 

Expedia's Price Tracking feature means you can stay on top of airfares without manually checking every day. It sends you automated price alerts for cheap St. Louis to Washington flights and uses historical data to indicate when the best time to book is. Download Expedia's free app to activate this handy tool in a few easy taps.

 

You could also save big by booking one of Expedia's vacation packages. Bundling together your St. Louis to Washington airfare with your accommodations and car rental is often cheaper than booking everything separately. There’s also One Key, Expedia's generous rewards program. Join for free and you could earn One Key cash on most bookings to save on future adventures.

 

*Terms apply.

 

Disclaimer: ARC The statistics are based on average round-trip ticket prices between January and August 2023. The percentages you see are averages.

 

St. Louis to Washington Flights

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*Available to One Key members.