Cheap Flights from St. Louis (XLS) to Seattle (SEA)

Popular airlines from St. Louis (XLS) to Seattle

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Frequently asked questions

How much does a flight from St. Louis (XLS) to Seattle - Tacoma Intl. Airport (SEA) cost?
Get a cheap one-way flight or cheap return flight from St. Louis (XLS) to Seattle - Tacoma Intl. Airport (SEA) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to see our cheapest flight offers on this route.
What is the cheapest month to fly from St. Louis (XLS) to Seattle - Tacoma Intl. Airport (SEA)?
Planning your trip for may help you find better deals, as it's the cheapest month for flights between XLS and SEA. You'll typically find the lowest prices during the off-season.
What is the cheapest airline that flies from St. Louis (XLS) to Seattle - Tacoma Intl. Airport (SEA)?
To find the cheapest airline flying from XLS to SEA, use Expedia's filter tool. Tailor your search based on your travel needs, such as preferred carriers and number of stops. You can then sort your results by "Price (lowest to highest)" to see the cheapest fares upfront.
How many flights per day from St. Louis (XLS) to Seattle - Tacoma Intl. Airport (SEA)?
There aren't any daily nonstop flights departing from St. Louis (XLS) to Seattle - Tacoma Intl. Airport (SEA). But you can opt for flights with layovers. Filter your search on Expedia to include one or two stops, and you'll be on your way in no time.
What day of the week has the most flights from XLS to SEA?
Generally you'll find the largest variety of flight choices on a Friday. Tuesdays tend to be the quietest.* But this can vary depending on the season, carrier 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 Seattle - Tacoma Intl. Airport (SEA)?
To land at Seattle - Tacoma Intl. Airport (SEA) without delays, opt for a flight that takes off from St. Louis (XLS) before 3 PM. The likelihood of cancellations is 22% higher, on average, for departures after this time.**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 Seattle - Tacoma Intl. Airport (SEA) last-minute?
Booking your ticket from XLS to SEA right before your getaway is usually more expensive. However, if you're flexible with your departure dates and times, you could score a cheap last-minute fare.
Is it cheaper to book a XLS to SEA flight and hotel package?
You'll typically save money by booking a XLS to SEA flight and hotel package compared to booking separately. In fact, you could save hundreds of dollars by bundling with Expedia. And it's simple to manage everything in one convenient place. After selecting your ideal flights and accommodations, you can add extras like car rentals, tours and activities.
Can I cancel or change the date of my flight from St. Louis (XLS) to Seattle - Tacoma Intl. Airport (SEA)?
Generally, it's possible to reschedule or cancel your XLS to SEA flight. However, if the booking was made more than 24 hours ago, additional fees may apply. Check your airline's policies in your itinerary to see what changes are allowed and if any costs are involved. You'll also find more details on our Customer Service portal.

Travel information

Origin airport
St. Louis
Destination airport
Seattle - Tacoma Intl.
Distance
6114 mi

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St. Louis to Seattle Flights

The cheapest times to fly from St. Louis to Seattle

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 Seattle are during the month of . You can find some of the cheapest flights from St. Louis to Seattle with Expedia's search tool and vast selection of airlines.

 

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

Sunday is one of the best days to book for cheap flights from St. Louis to Seattle: 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 Seattle

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 Seattle in 2026. 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 Seattle 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 Seattle 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 Seattle Flights

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