Fly from Seattle to London for $773 round-trip, including all taxes, on Air Canada.
We found seats departing SEA on Monday, March 17, and returning from LHR on Monday, March 24. Other travel dates available for travel in March, though seats are scarce. Flights connect in Toronto.
For booking info, see our Fare Details.
All products and services mentioned on Airfarewatchdog are independently selected by our team of expert travelers. If you buy something through our links, we may earn an affiliate commission.