AirHint found the following cheapest one-way flights from Seattle (SEA) to Porto (OPO) in May 2026 (see full year).
One-Way flights
| 17 May | British Airways | ||
| 18 May | British Airways | ||
| 14 May | Delta | ||
| 16 May | British Airways | ||
| 24 May | United | ||
| 25 May | Air France | ||
| 26 May | Delta | ||
| 27 May | Air France | ||
| 31 May | Air France | ||
| 06 May | Lufthansa |
Also check the deals for return flights from Seattle to Porto in May.
Powered by
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.
Find us on social media