Cheapest return flights from Seattle to Lisbon in September from 492€

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

Return flights

27 Sep - 05 Oct Icelandair
04 Sep - 14 Sep Icelandair
03 Sep - 17 Sep Icelandair
08 Sep - 30 Sep Aer Lingus
04 Sep - 13 Sep Icelandair
24 Sep - 09 Oct Turkish Airlines
03 Sep - 02 Oct Aer Lingus
17 Sep - 27 Sep Icelandair
20 Sep - 30 Sep Icelandair

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

Skyscanner

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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