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

You’ll discover affordable return Alaska Airlines flights from SEA to STL by organizing your results from “Price (lowest to highest)” on Expedia. Or search for bargains for a one-way journey.**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.

Browse for one-way or return flights to St. Louis in January or February. You could find lower fares with Alaska Airlines during these off-peak travel months.

Start searching one to three months ahead of your travel date to get cheaper fares on Alaska Airlines flights from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL). You can save 25% by booking your domestic flight 34 to 86 days in advance versus last-minute reservations made 6 to 12 days out. You could also cut costs by buying your fare on a Sunday, as it’s 6% cheaper on average than a Monday, the most expensive day to book.* Get your timing right, and you can enjoy significant savings on domestic trips.*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.

You can easily fly from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL) on one of Alaska Airlines’s 7 direct weekly flights. Apply our “Nonstop” and “Airline” filters to find the Alaska Airlines flight that’ll get you to STL at a time that suits you.

It takes approximately 3h 52m to travel nonstop from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL) with Alaska Airlines.

If you’re looking for flexibility, Thursday offers the most choice for Alaska Airlines flights from Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL). You can pick from 2 different departures.

Setting off from SEA at 8:00AM UTC-8, the earliest Alaska Airlines flight to STL arrives at 1:53PM UTC-6. Flying early means you’re less likely to encounter delays or cancellations.* Prefer a later start? The last Alaska Airlines flight from SEA to STL departs at 6:09PM UTC-8 and touches down at 11:59PM UTC-6.*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.

Lambert-St. Louis Intl. Airport (STL) is the primary St. Louis hub for Alaska Airlines flights from Seattle - Tacoma Intl. Airport (SEA).

Alaska Airlines makes traveling from SEA to STL more enjoyable with a rewarding loyalty program and an excellent in-flight experience. You may even earn points with Mileage Plan. Don’t forget to join our free One Key™ rewards program to earn OneKeyCash™*, which can be redeemed on future travel.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.

For the Seattle - Tacoma Intl. Airport (SEA) to Lambert-St. Louis Intl. Airport (STL) route, Alaska Airlines typically flies Boeing 737 MAX 9 and Boeing 737-800 planes. Remember that last-minute changes can occur for operational purposes, meaning your flight may be on a different aircraft.

Depending on your ticket type, a fee typically applies if you change or cancel your booking more than 24 hours after it’s confirmed. To secure tickets with more flexibility, select our “No cancel fee” or “Changes included” filter when you search for flights. For more details on canceling or changing your reservation, visit “Trips,” select your flight and click on “Manage Booking.”