Cheapest return flights from Seattle to Keflavik in September from 319€

AirHint found the following cheapest return flights from Seattle (SEA) to Keflavik (KEF) in September 2025 (see full year).

Return flights

02 Sep - 09 Sep Air Canada
02 Sep - 09 Sep Icelandair direct
25 Sep - 02 Oct Icelandair direct
29 Sep - 06 Oct Icelandair direct
30 Sep - 07 Oct Icelandair direct
01 Sep - 08 Sep Icelandair direct
03 Sep - 10 Sep Icelandair direct
23 Sep - 30 Sep Icelandair direct
04 Sep - 11 Sep Icelandair direct
05 Sep - 12 Sep Icelandair direct
06 Sep - 13 Sep Icelandair direct
09 Sep - 16 Sep Icelandair direct
10 Sep - 17 Sep Icelandair direct
23 Sep - 08 Oct Icelandair direct
24 Sep - 01 Oct Icelandair direct
26 Sep - 03 Oct Icelandair direct
28 Sep - 05 Oct Icelandair direct
27 Sep - 08 Oct KLM

Also check the deals for one-way flights from Seattle to Keflavik in September.

Skyscanner

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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