$84 Cheap Flights from St. Louis (STL) to Seattle (SEA)

View $84 flight on Sat, Nov 1, 2025Opens in a new window

Popular airlines from St. Louis Lambert Intl. Airport (STL) to Seattle-Tacoma International Airport (SEA)

Cheap Flights from St. Louis to Seattle (STL-SEA)

Prices were available within the past 7 days and start at $84 for one-way flights and $168 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Southwest Airlines
Sat, Nov 1 - Wed, Nov 5
STL
St. Louis
SEA
Seattle
$168 Roundtrip, found 1 hour ago
$168
Roundtrip
found 1 hour ago
Select Southwest Airlines flight, departing Sat, Nov 1 from St. Louis to Seattle, returning Wed, Nov 5, priced at $168 found 1 hour ago
Southwest Airlines
Sat, Nov 1 - Wed, Nov 5
STL
St. Louis
SEA
Seattle
$172 Roundtrip, found 1 hour ago
$172
Roundtrip
found 1 hour ago
Select Southwest Airlines flight, departing Sat, Nov 1 from St. Louis to Seattle, returning Wed, Nov 5, priced at $172 found 1 hour ago
Delta
Tue, Oct 28 - Tue, Nov 4
STL
St. Louis
SEA
Seattle
$174 Roundtrip, found 1 hour ago
$174
Roundtrip
found 1 hour ago
Select Delta flight, departing Tue, Oct 28 from St. Louis to Seattle, returning Tue, Nov 4, priced at $174 found 1 hour ago
American Airlines
Tue, Oct 28 - Tue, Nov 4
STL
St. Louis
SEA
Seattle
$177 Roundtrip, found 1 hour ago
$177
Roundtrip
found 1 hour ago
Select American Airlines flight, departing Tue, Oct 28 from St. Louis to Seattle, returning Tue, Nov 4, priced at $177 found 1 hour ago
Southwest Airlines
Tue, Oct 28 - Tue, Nov 4
STL
St. Louis
SEA
Seattle
$178 Roundtrip, found 1 hour ago
$178
Roundtrip
found 1 hour ago
Select Southwest Airlines flight, departing Tue, Oct 28 from St. Louis to Seattle, returning Tue, Nov 4, priced at $178 found 1 hour ago
Delta
Tue, Jan 6 - Wed, Jan 14
STL
St. Louis
SEA
Seattle
$178 Roundtrip, found 2 hours ago
$178
Roundtrip
found 2 hours ago
Select Delta flight, departing Tue, Jan 6 from St. Louis to Seattle, returning Wed, Jan 14, priced at $178 found 2 hours ago
American Airlines
Wed, Oct 29 - Sat, Nov 1
STL
St. Louis
SEA
Seattle
$179 Roundtrip, found 4 hours ago
$179
Roundtrip
found 4 hours ago
Select American Airlines flight, departing Wed, Oct 29 from St. Louis to Seattle, returning Sat, Nov 1, priced at $179 found 4 hours ago
Southwest Airlines
Tue, Oct 28 - Tue, Nov 4
STL
St. Louis
SEA
Seattle
$182 Roundtrip, found 1 hour ago
$182
Roundtrip
found 1 hour ago
Select Southwest Airlines flight, departing Tue, Oct 28 from St. Louis to Seattle, returning Tue, Nov 4, priced at $182 found 1 hour ago
Alaska Airlines
Tue, Oct 28 - Tue, Nov 4
STL
St. Louis
SEA
Seattle
$184 Roundtrip, found 1 hour ago
$184
Roundtrip
found 1 hour ago
Select Alaska Airlines flight, departing Tue, Oct 28 from St. Louis to Seattle, returning Tue, Nov 4, priced at $184 found 1 hour ago
United
Mon, Nov 10 - Tue, Nov 11
STL
St. Louis
SEA
Seattle
$192 Roundtrip, just found
$192
Roundtrip
just found
Select United flight, departing Mon, Nov 10 from St. Louis to Seattle, returning Tue, Nov 11, priced at $192 just found

Find the cheapest month to fly from St. Louis (STL) to Seattle (SEA)

November is typically the cheapest month to fly

From $140 - $352 per traveler.

Frequently asked questions

How much does a flight from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA) cost?
Grab a cheap one-way flight from $84 or cheap return flight from $168 from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA) with Expedia. Enter your travel dates and sort by "Price (lowest to highest)" to find our cheapest flight offers on this route.
What is the cheapest month to fly from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA)?
The cheapest month to fly from STL to SEA is November, when demand is low. Off-peak season is generally when airlines offer lower prices between these airports.
Which airlines fly direct from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA)?
You can travel nonstop from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA) on an Alaska Airlines flight.
What is the cheapest airline that flies from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA)?
Use the filter tool on Expedia to compare airlines and find the most affordable carrier that'll take you from STL to SEA. Then, sort your results by "Price (lowest to highest)" to snap up a good deal.
How many flights per day from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA)?
On average, there's only 1 direct flight departing from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA) every day. If this doesn't fit your plans, think about flights with layovers. Simply filter your search on Expedia to include one stop or more to find a better alternative.
What are the most popular departure times for flights from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA)?
Flights between STL and SEA tend to be busiest at 2 PM. If you'd like a more relaxed atmosphere and possibly cheaper tickets, look for a departure outside the usual busy windows.
What day of the week has the most flights from STL to SEA?
Sunday offers the most flights from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA). Consider leaving on this day and you'll have the best chance of finding a departure that works with your plans.
What is the earliest flight from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA)?
Catch the earliest flight at around 7:00AM UTC-6, heading out of Lambert-St. Louis Intl. Airport (STL). You'll be in the air for around 4h 42m, reaching Seattle - Tacoma Intl. Airport (SEA) at approximately 9:42AM UTC-8.
How long does it take to fly from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA)?
It takes around 4 hours and 41 minutes to travel the 1,700 mi from STL to SEA.
What is the best time to fly from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA)?
To avoid possible delays on the Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA) route, travel before 3 PM. Flights after this time have a 22% higher chance of being canceled.**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.
What airports do you fly into for Seattle from Lambert-St. Louis Intl. Airport (STL)?
If you're taking a direct flight from Lambert-St. Louis Intl. Airport (STL) to Seattle, Seattle - Tacoma Intl. Airport (SEA) is the only airport you can touch down at.
Is it cheaper to buy a plane ticket from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA) last-minute?
Holding off until just before your trip to book your flight from STL to SEA often results in higher prices. While you might find some last-minute deals, they're not always guaranteed. Be flexible with your travel plans for the best chance of scoring a bargain.
Is it cheaper to book a STL to SEA flight and hotel package?
Compared with arranging flights and hotels separately, booking a STL to SEA flight and hotel package with Expedia could result in significant savings. Better yet, having everything in one convenient place will take the hassle out of travel planning. Just pick your flights and choose from our wide range of hotels, then personalize your trip with other add-ons like tours, activities and car rentals.
Can I cancel or change the date of my flight from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA)?
Usually, it's possible to reschedule or cancel your STL to SEA flight. However, if the booking was made more than 24 hours ago, additional charges may apply. Check your airline's policies in your itinerary to see what changes are allowed and whether any costs are involved. You'll also find further details on our Customer Service portal.

Travel information

Travel information

Origin airport
Lambert-St. Louis Intl.
Destination airport
Seattle - Tacoma Intl.
Airlines serving
Alaska Airlines, American Airlines, Delta, Frontier Airlines, Hawaiian Airlines, Southwest Airlines, United
Roundtrip price
$167
Distance
1705 mi
Average flight time
2 hours 30 mins

Book with confidence

Book with confidence

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 November. 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 2025. You can also book with separate airlines for your outbound and return journeys, from $84 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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*Available to One Key members.