STL to SEA Flight Deals: Your Gateway to the Emerald City
Cheapest flight found
$150
Last updated Mar 13, 2026
Prices by Month
Price History
Tracking the Jun 4, 2026 departure — the cheapest date we found.
Price Behavior: STL → SEA
Based on 6 months of fare data collected by Trip Manta.
Lowest Fare
$150
Highest Fare
$180
Median Fare
$174
Price Spread
$30
Prices stay relatively stable on this route.
Cheapest month to fly: June 2026 (from $150)
Most expensive month: September 2026 (from $180)
Biggest price drop caught: $65 between consecutive checks
Most frequent cheapest airline: United
What This Means for You
Flights from St. Louis to Seattle range from $150 to $180, a $30 spread across the months we track. If your dates are flexible, June 2026 tends to have the lowest fares. Prices are relatively stable on this route, so you may not need to wait long for a good deal. Tracking still helps you confirm you are getting a fair price. We have caught drops as large as $65 between hourly checks on this route.
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From
St. Louis (STL)
To
Seattle (SEA)
Airport Information
St. Louis (STL)
St. Louis Lambert International Airport (STL) serves as the primary aviation hub for Missouri, boasting a rich history as one of the oldest municipal airports in the United States. It features two main terminals and serves as a significant focus city for Southwest Airlines. Travelers can enjoy local culinary favorites like the Pasta House or Schlafly Beer while waiting for their departure, and the airport is easily accessible via the MetroLink light rail system from downtown.
Seattle (SEA)
Seattle-Tacoma International Airport (SEA), commonly known as Sea-Tac, is the largest airport in the Pacific Northwest region and a major gateway to Asia. Located about 14 miles south of downtown Seattle, it offers a wide array of amenities including impressive local art installations and live musical performances in the terminal. The Link Light Rail provides a convenient and affordable connection from the airport terminal directly to the heart of the city, making it easy for visitors to reach their destination.
Frequently Asked Questions
How long is the flight from STL to SEA?
A direct flight usually takes around 4 hours and 45 minutes, though the return flight from Seattle to St. Louis is often slightly shorter due to prevailing jet stream tailwinds.
Which airlines offer non-stop flights between St. Louis and Seattle?
Alaska Airlines and Southwest Airlines are the primary carriers that provide non-stop service on this specific route, though availability can vary by season.
Is there a time difference between St. Louis and Seattle?
Yes, Seattle is in the Pacific Time Zone, which is two hours behind the Central Time Zone used in St. Louis.
What is the best way to get from Sea-Tac to downtown Seattle?
The Sound Transit Link Light Rail is highly recommended as it avoids heavy highway traffic and drops passengers off at several central downtown locations for a low flat fare.
What is the distance between STL and SEA?
The Great Circle distance between St. Louis Lambert International Airport and Seattle-Tacoma International Airport is approximately 1,710 miles.
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