$119 Cheap Alaska Airlines flights St. Louis (STL) to Seattle (SEA)

Scoring cheap one-way Alaska Airlines flights from STL to SEA from $119 on Expedia couldn’t be easier — just filter by “Price (lowest to highest).” Alternatively, check out our budget-friendly round-trip fares from $210 for your next getaway.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Search for one-way or return flights to Seattle in January or February. You could find an affordable fare with Alaska Airlines during these quieter months.

Search for affordable Alaska Airlines flights from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA) one to three months before your departure. Travelers who book domestic flights 34 to 86 days in advance can save 25% compared to those who book just 6 to 12 days ahead. Regardless of fare type and journey, the best day to book a domestic flight is generally Sunday and the most expensive is typically Monday. Passengers who book on a Sunday can save 6% on average compared to those who book their travel on a Monday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC’s global airline sales database.

Jet off on one of Alaska Airlines’s 7 direct weekly flights from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA). To see what’s available, enter your origin, dates and destination and hit search. Next, apply the “Nonstop” and “Airline” filters.

It takes approximately 4h 41m to fly nonstop from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA) with Alaska Airlines.

Alaska Airlines operates the most flights from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA) on Saturday. With up to 2 daily departures, you’ll get the most choice and flexibility on this day.

Departing STL at 7:00AM UTC-6, the first Alaska Airlines flight to SEA lands at 9:42AM UTC-8. Traveling early means you’ll be less likely to experience cancellations.* Not a morning person? The last Alaska Airlines flight from STL to SEA departs at 2:49PM UTC-6 and touches down at 5:30PM UTC-8.*Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG’s global flight data platform.

Alaska Airlines flights from Lambert-St. Louis Intl. Airport (STL) to Seattle arrive at Seattle - Tacoma Intl. Airport (SEA). This is the main gateway to this city.

Heading from STL to SEA with Alaska Airlines comes with plenty of perks, including an excellent in-flight experience and a rewarding loyalty program. Plus, when you book through Expedia, One Key™ members can earn OneKeyCash™* to use on select future travel purchases. That’s in addition to the Mileage Plan points you can earn with Alaska Airlines.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.

You’ll likely board a Boeing 737 MAX 9 or a Boeing 737-800 when flying Alaska Airlines from Lambert-St. Louis Intl. Airport (STL) to Seattle - Tacoma Intl. Airport (SEA). However, keep in mind that a different aircraft could be assigned to your route due to operational requirements.

Depending on the type of fare you purchased, a fee may apply if you modify or cancel your booking more than 24 hours after it’s been confirmed. To find flexible plane tickets, select our “Changes included” or “No cancel fee” filter while looking for flights. For more details on modifying or canceling your reservation, head to “Trips,” select your flight and tick “Manage Booking.”