Flights from Seattle, WA to London, United Kingdom
Compare prices from 900+ airlines and find the best deals on flights from SEA to LHR.*Prices shown are estimated based on historical data.
Seattle, WA to London, United Kingdom
Round-trip flights from SEA to LHR typically cost $728-$910 USD. Prices vary by season, demand, and how far in advance you book. The lowest fares are usually found 6-8 weeks before departure for domestic routes.
Non-stop flights from SEA to LHR take approximately 13h 39m. Actual flight times vary based on weather, air traffic, and aircraft type. Consider arriving at the airport 2 hours before domestic departures.
Airlines operating SEA to LHR include American Airlines, Frontier Airlines, Emirates, Azul Brazilian Airlines and 1 more carriers. Each airline offers different fare classes, baggage policies, and loyalty programs. Compare options to find the best value for your travel needs.
The cheapest day to fly SEA to LHR is typically Tuesday. Mid-week flights are 10-20% cheaper than weekend departures. For best prices, book 6-8 weeks before your trip. Avoid booking less than 2 weeks out when fares spike.
Fares range from $728 to $1365 depending on dates, class, and airline.
Prices based on 500 searches. Updated hourly.
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About Flights from Seattle, WA to London, United Kingdom
Looking for cheap flights from Seattle, WA (SEA) to London, United Kingdom (LHR)? You've come to the right place. Fly2Any compares prices from over 900 airlines to help you find the best deals on this popular route.
Flight Information
Flights from SEA to LHR typically take around 13h 39m. The flight covers a distance of 6311 miles. Multiple airlines operate this route, including American Airlines, Frontier Airlines, Emirates, Azul Brazilian Airlines, United Airlines.
Best Time to Book
For the best prices on SEA to LHR flights, we recommend booking 2-3 months in advance. Prices tend to be lowest for mid-week departures (Tuesday and Wednesday). Use our Price Calendar feature to compare prices across different dates and find the cheapest options.
Price data last updated: April 2026
Airlines on This Route
Several major airlines serve the Seattle, WA to London, United Kingdom route, including:
- American Airlines (AA)
- Frontier Airlines (F9)
- Emirates (EK)
- Azul Brazilian Airlines (AD)
- United Airlines (UA)
Frequently Asked Questions - SEA to LHR Flights
How long is the flight from Seattle, WA to London, United Kingdom?
Direct flights from Seattle, WA (SEA) to London, United Kingdom (LHR) take approximately 13h 39m. Connecting flights may add 2-4 hours depending on layover location. For the fastest journey, look for nonstop flights which are typically available on this popular route.
When is the best time to book SEA to LHR flights?
For the best prices on SEA to LHR flights, book 6-8 weeks in advance for domestic routes or 2-4 months ahead for international travel. Shoulder seasons (April-May, September-October) offer good weather and moderate prices. Peak season months (June, July) have higher prices, while January and February typically offer the best deals.
What are the cheapest days to fly from Seattle, WA to London, United Kingdom?
Tuesday and Wednesday departures are typically 15-25% cheaper than weekend flights on the SEA to LHR route. Saturday is usually the most expensive day to fly. For additional savings, consider red-eye flights or early morning departures, which often have lower fares and less crowded airports.
Which airlines fly from SEA to LHR?
Major carriers on this route include Alaska Airlines, Delta, and other domestic and international airlines. Seattle-Tacoma is Alaska Airlines main hub with strong connections to West Coast and Asian destinations.
What should I know about flying from Seattle, WA airport?
Seattle-Tacoma is Alaska Airlines main hub with strong connections to West Coast and Asian destinations. Book flights that depart mid-morning or early afternoon for the smoothest experience - these times typically have shorter security lines and fewer delays.
What is the cheapest month to fly from Seattle, WA to London, United Kingdom?
The cheapest months to fly from SEA to LHR are typically January, February, November. Shoulder seasons (April-May, September-October) offer good weather and moderate prices. Avoid peak travel periods like June and July when prices can be 30-50% higher. Use Fly2Any's price alerts to get notified when fares drop.
What is the baggage allowance for SEA to LHR flights?
Baggage allowances vary by airline and fare class. Most full-service carriers include one checked bag (up to 50 lbs) on this route. Budget carriers may charge $25-$60 for checked bags. All airlines allow one personal item free. Compare total costs including baggage fees when booking to get the best deal.
Are there direct flights from Seattle, WA to London, United Kingdom?
Yes, several airlines offer nonstop flights from SEA to LHR. Direct flights take approximately 13h 39m. If you're flexible with your schedule, connecting flights through major hubs like ATL or ORD may offer lower prices.
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