$199 Cheap American Airlines flights Boston (BOS) to London (LHR)

Make use of the "Price (lowest to highest)" filter on Expedia to look for cheap American Airlines return flights from $390 from BOS to LHR. Affordable one-way tickets from $199 are also on offer.**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.

Start your search for American Airlines flights from BOS to LHR about one month before you want to leave. The most affordable time to book 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. No matter your fare class and itinerary, the best day to book international airfare is usually Sunday. Friday can be the most expensive. Passengers who book on a Sunday can save 17% on average 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.

The earliest American Airlines flight from BOS to LHR departs at 8:20PM UTC-5, arriving at 7:50AM UTC+0. If you'd like to head off later, the last American Airlines flight leaves BOS at 8:20PM UTC-5 and lands at LHR at 7:50AM UTC+0. Flying before noon is often a good option as morning and mid-morning flights tend to experience fewer 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.