Cheapest return flights from Seattle to Lisbon in September from 547€

Best time to book flights for Seattle (SEA) to Lisbon (LIS) flights at AirHint

AirHint found the following cheapest return flights from Seattle (SEA) to Lisbon (LIS) in September 2025 (see full year).

Return flights

06 Sep - 14 Sep Icelandair
02 Sep - 09 Sep Icelandair
26 Sep - 06 Oct British Airways
25 Sep - 06 Oct British Airways
03 Sep - 10 Sep Scandinavian Airlines
01 Sep - 08 Sep Scandinavian Airlines
04 Sep - 11 Sep Turkish Airlines
27 Sep - 30 Sep Turkish Airlines
14 Sep - 04 Oct Turkish Airlines

Also check the deals for one-way flights from Seattle to Lisbon in September.

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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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