Cheap Flights from Seattle to South London

View €258 flight on Mon, 16 Mar 2026Opens in a new window

Popular airlines from Seattle to South London

  • British Airways

    British Airways

  • Aer Lingus

    Aer Lingus

  • Finnair

    Finnair

  • Lufthansa

    Lufthansa

  • Iberia

    Iberia

  • Air Canada

    Air Canada

  • Alaska Airlines

    Alaska Airlines

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Cheap flights from Seattle to South London (SEA-LON)

Prices were available within the past 7 days and start at €258 for one-way flights and €413 for round trip, for the period specified. Prices and availability are subject to change. Additional terms apply.

Aer Lingus
Wed, 15 Oct - Wed, 22 Oct
SEA
Seattle
LHR
London
€413 Return, found 4 days ago
€413
Return
found 4 days ago
Select Aer Lingus flight, departing Wed, 15 Oct from Seattle to London, returning Wed, 22 Oct, priced at €413 found 4 days ago
Delta
Wed, 21 Jan - Wed, 28 Jan
SEA
Seattle
LHR
London
€437 Return, found 3 days ago
€437
Return
found 3 days ago
Select Delta flight, departing Wed, 21 Jan from Seattle to London, returning Wed, 28 Jan, priced at €437 found 3 days ago
Virgin Atlantic
Sun, 17 Aug - Tue, 2 Sep
SEA
Seattle
LHR
London
€442 Return, found 2 hours ago
€442
Return
found 2 hours ago
Select Virgin Atlantic flight, departing Sun, 17 Aug from Seattle to London, returning Tue, 2 Sep, priced at €442 found 2 hours ago
British Airways
Wed, 21 Jan - Wed, 28 Jan
SEA
Seattle
LHR
London
€443 Return, found 3 days ago
€443
Return
found 3 days ago
Select British Airways flight, departing Wed, 21 Jan from Seattle to London, returning Wed, 28 Jan, priced at €443 found 3 days ago
Icelandair
Wed, 21 Jan - Wed, 28 Jan
SEA
Seattle
LGW
London
€445 Return, found 3 days ago
€445
Return
found 3 days ago
Select Icelandair flight, departing Wed, 21 Jan from Seattle to London, returning Wed, 28 Jan, priced at €445 found 3 days ago
Iberia
Wed, 21 Jan - Wed, 28 Jan
SEA
Seattle
LHR
London
€448 Return, found 3 days ago
€448
Return
found 3 days ago
Select Iberia flight, departing Wed, 21 Jan from Seattle to London, returning Wed, 28 Jan, priced at €448 found 3 days ago

Find the cheapest month to fly from Seattle (SEA) to London (LHR)

October is typically the cheapest month to fly

From €412 - €650 per traveller.

Graph displaying average flight prices per month

*Available to Expedia members.