$401 Cheap United flights Seattle (SEA) to Reykjavik (KEF)

You can discover affordable return United Airlines flights from $422 from SEA to KEF by sorting your results from "Price (lowest to highest)" on Expedia. Or search for deals from $401 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.

Snagging the best United Airlines deals from SEA to KEF often comes down to timing. You can save 17% on international flights when you book 18 to 29 days before takeoff instead of four to five months ahead. What's more, you can pocket 17% on average by buying your tickets on a Sunday compared to a Friday, which is often the most expensive day to book.* It's a good idea to start searching for flights about one month before you want to travel.*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.

To find the earliest departures from SEA to KEF with United Airlines, sort your results by "Morning" and "Early Morning." Choosing an early flight generally means 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.

Travel from SEA to KEF with United Airlines and you can look forward to a host of benefits including a rewarding loyalty program. When booking through Expedia as a United Mileage Plus and One Key™ member, you may also earn OneKeyCash™* to use on select future travel purchases.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.