AirHint found the following cheapest one-way flights from Seattle (SEA) to London (LHR) in April 2026 (see full year).
One-Way flights
| 14 Apr | WestJet | ||
| 20 Apr | WestJet | ||
| 18 Apr | WestJet | ||
| 23 Apr | WestJet | ||
| 02 Apr | Air Canada | ||
| 04 Apr | WestJet | ||
| 24 Apr | WestJet | ||
| 09 Apr | Alaska Airlines | ||
| 03 Apr | Air Canada | ||
| 07 Apr | Air Canada |
Also check the deals for return flights from Seattle to London in April.
The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.
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