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Compare prices across airlines and find the best deals
Prices are typically lower on Thursday and in January.
Compare prices across airlines to find the best deal. Prices can vary significantly.
Flying midweek or in off-peak seasons can save you up to 30% on airfare.
Booking 6+ weeks in advance typically offers the best prices.
Airlines operating flights from Seattle to London include Finnair, Aeromexico, American Airlines, Aer Lingus, Icelandair, SAS, Air Canada, United Airlines, Austrian, Brussels Airlines, Lufthansa, Virgin Atlantic, China Airlines, Alaska Airlines, British Airways, WestJet, Turkish Airlines.
The cheapest month to fly is January, and departing on Thursdays typically offers the best fares. Book 6–8 weeks ahead for the best prices.
Book at the right time: For international flights, aim to book 6–10 weeks ahead. Last-minute fares on Seattle to London are rarely cheap, and prices spike sharply within 2 weeks of departure.
Shift your dates by a day or two: Thursdays are typically the cheapest day to fly this route. Avoiding Friday and Sunday departures can save significantly. January is historically the cheapest month on this route.
Weigh up connecting flights: Connecting flights on Seattle to London can be 20–40% cheaper than direct options. If you have time to spare, it's worth comparing.
Factor in baggage fees: Low-cost carriers on this route often advertise attractive base fares but charge separately for checked luggage. Always compare the all-in price — a $20 cheaper fare plus $50 baggage fee is no saving. Finnair and Aeromexico may have different inclusions, so check each airline's fare conditions.
Search in private browsing: Some booking sites use cookies to track repeat searches and may show higher prices after multiple lookups. Use an incognito or private window — or just use Booked AI, which pulls live prices without any tracking markup.
Compare two one-ways against a return: On some international routes, booking a one-way with one airline and the return with another can undercut a standard return ticket — especially if a budget carrier covers one direction. Check both options with the flexible dates calendar above.
The cheapest flights from Seattle to London start from $653, with typical prices ranging from $653 to $953.
The typical flight time from Seattle to London is approximately 15 hours and 36 minutes.
Airlines operating this route include Finnair, Aeromexico, American Airlines, Aer Lingus, Icelandair, SAS, Air Canada, United Airlines, Austrian, Brussels Airlines, Lufthansa, Virgin Atlantic, China Airlines, Alaska Airlines, British Airways, WestJet, Turkish Airlines.
Prices sourced via Duffel and updated regularly. All fares shown are indicative one-way prices in AUD and may vary at time of booking. Booked AI is an IATA-accredited travel platform.
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