Cheapest return flights from Seattle to Lisbon in September from 500€

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

Return flights

05 Sep - 12 Sep Icelandair
29 Sep - 06 Oct Icelandair
20 Sep - 27 Sep Icelandair
02 Sep - 09 Sep Aer Lingus
09 Sep - 16 Sep Aer Lingus
08 Sep - 16 Sep Aer Lingus
06 Sep - 13 Sep Icelandair
16 Sep - 23 Sep Aer Lingus
04 Sep - 11 Sep Icelandair
30 Sep - 07 Oct Aer Lingus
03 Sep - 10 Sep Aer Lingus
23 Sep - 07 Oct Aer Lingus
07 Sep - 14 Sep Aer Lingus
23 Sep - 01 Oct Hawaiian Airlines
27 Sep - 04 Oct Icelandair
27 Sep - 05 Oct Icelandair
24 Sep - 01 Oct Turkish Airlines
25 Sep - 02 Oct Turkish Airlines
25 Sep - 09 Oct Turkish Airlines
22 Sep - 01 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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