AirHint found the following cheapest return flights from Seattle (SEA) to Helsinki (HEL) in October 2025 (see full year).

Return flights

01 Oct - 08 Oct	Scandinavian Airlines
07 Oct - 14 Oct	Finnair
14 Oct - 21 Oct	Finnair
15 Oct - 22 Oct	Finnair
21 Oct - 28 Oct	Finnair
29 Oct - 05 Nov	Finnair
30 Oct - 06 Nov	Finnair
06 Oct - 13 Oct	Finnair
12 Oct - 19 Oct	Finnair
20 Oct - 27 Oct	Finnair
31 Oct - 07 Nov	Finnair
26 Oct - 02 Nov	Alaska Airlines
09 Oct - 16 Oct	Finnair
16 Oct - 23 Oct	Finnair
27 Oct - 03 Nov	Finnair
25 Oct - 01 Nov	Finnair
28 Oct - 04 Nov	Finnair

Also check the deals for one-way flights from Seattle to Helsinki in October.

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.

Book a cheap hotel in Helsinki

Cheap car rent in Helsinki

Cheapest return flights from Seattle to Helsinki in October from 377€

Return flights