AirHint found the following cheapest return flights from Seattle (SEA) to Lisbon (LIS) in August 2025 (see full year).
Return flights
| 16 Aug - 24 Aug | Icelandair | ||
| 29 Aug - 12 Sep | Icelandair | ||
| 20 Aug - 28 Aug | Icelandair | ||
| 20 Aug - 26 Aug | Icelandair | ||
| 17 Aug - 24 Aug | Lufthansa | ||
| 15 Aug - 23 Aug | Icelandair | ||
| 04 Aug - 07 Aug | Aer Lingus |
Also check the deals for one-way flights from Seattle to Lisbon in August.
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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