Cheapest one-way flights from Seattle to Barcelona in September from $430
AirHint found the following cheapest one-way flights from Seattle (SEA) to Barcelona (BCN) in September 2025 (see full year).
One-Way flights
| 19 Sep | Alaska Airlines | ||
| 04 Sep | Icelandair | ||
| 18 Sep | Turkish Airlines |
Also check the deals for return flights from Seattle to Barcelona in September.
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.
