Cheap British Airways flights Seattle (SEA) to Southampton (SOU)

Apply the "Price (lowest to highest)" filter on Expedia to search for cheap British Airways return flights from SEA to SOU. Affordable one-way options are available as well.**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 British Airways flights from SEA to SOU about one month before you want to leave. The most affordable time to reserve an international flight is generally 18 to 29 days ahead of your travel date when you can save 17% versus booking four to five months in advance. Regardless of itinerary or fare class, the best day of the week to book international airfare is usually Sunday. Friday can be the most expensive. Passengers booking on a Sunday can save an average of 17% compared to those who book on a Friday.**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.

Sort your results by "Early Morning" and "Morning" to see the earliest flights from SEA to SOU. Taking off early means flight cancellations are less likely.**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.

British Airways makes traveling from SEA to SOU more comfortable with a 4-star airline rating and an excellent in-flight experience. You could even start earning points with British Airways Executive Club. Make sure you sign up to Expedia's free One Key™ rewards program to earn OneKeyCash™*, which can be redeemed on future bookings.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.