Cheapest return flights from Seattle to Lisbon in December from 423€

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

Return flights

29 Dec - 24 Jan KLM
31 Dec - 12 Jan United
04 Dec - 09 Dec United
28 Dec - 17 Jan Air France
27 Dec - 17 Jan United
31 Dec - 07 Jan Air France
24 Dec - 17 Jan British Airways
06 Dec - 27 Dec United
07 Dec - 27 Dec United
25 Dec - 17 Jan British Airways
22 Dec - 17 Jan Frontier Airlines
24 Dec - 07 Jan Delta
23 Dec - 30 Dec Hawaiian Airlines
15 Dec - 04 Jan Hawaiian Airlines
19 Dec - 27 Dec Alaska Airlines

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

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