AirHint found the following cheapest return flights from Seattle (SEA) to Lisbon (LIS) in March 2026 (see full year).

Return flights

09 Mar - 16 Mar	Air Canada
05 Mar - 12 Mar	Air Canada
06 Mar - 13 Mar	Lufthansa
10 Mar - 17 Mar	Alaska Airlines
11 Mar - 18 Mar	Alaska Airlines
12 Mar - 19 Mar	Alaska Airlines
07 Mar - 14 Mar	Alaska Airlines
08 Mar - 15 Mar	Air Canada
14 Mar - 21 Mar	British Airways
13 Mar - 20 Mar	British Airways

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

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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Cheapest return flights from Seattle to Lisbon in March from 442€

Return flights