$395 Cheap Icelandair flights Washington (IAD) to London (LGW)

You can find affordable round-trip Icelandair flights from $409 from IAD to LGW by sorting your results from "Price (lowest to highest)" on Expedia. Or search for options from $395 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.

Landing the best Icelandair deals from IAD to LGW 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. As an added bonus, you can pocket 17% on average by buying your tickets on a Sunday compared to a Friday, which is usually the most expensive day to book.* It's smart to kick off your flight search about one month before your travel dates.*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.

Filter your results by "Morning" and "Early Morning" to find the earliest departures from IAD to LGW. Jetting off early means you're 20% less likely to experience cancellations.**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.

Offering a rewarding loyalty program and top-tier customer service, Icelandair is a favorite for many passengers flying from IAD to LGW. Also, if you're an Icelandair Saga Club and One Key™ member booking with Expedia, you could earn OneKeyCash™* on eligible flights on top of your airline miles, which can be put toward future travel.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.