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

Return flights

25 Oct - 16 Nov	Icelandair
25 Oct - 02 Nov	Icelandair
27 Oct - 04 Nov	United
29 Oct - 06 Nov	United
28 Oct - 05 Nov	United
31 Oct - 08 Nov	Lufthansa
14 Oct - 22 Oct	Aer Lingus
26 Oct - 03 Nov	Air France
24 Oct - 16 Nov	Air France
30 Oct - 07 Nov	Air France
08 Oct - 16 Oct	Air France
13 Oct - 20 Oct	Lufthansa
11 Oct - 19 Oct	Icelandair
13 Oct - 21 Oct	British Airways
07 Oct - 15 Oct	Aer Lingus
15 Oct - 23 Oct	SWISS
18 Oct - 26 Oct	Icelandair
16 Oct - 24 Oct	Lufthansa
23 Oct - 31 Oct	United
24 Oct - 01 Nov	Lufthansa

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

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.

Book a cheap hotel in Lisbon

Cheap car rent in Lisbon

Cheapest return flights from Seattle to Lisbon in October from $480

Return flights