Cheapest return flights from Seattle to Keflavik in August from 350€

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

Return flights

15 Aug - 18 Aug Icelandair direct
07 Aug - 13 Aug Icelandair direct
12 Aug - 19 Aug Icelandair direct
13 Aug - 20 Aug Icelandair direct
14 Aug - 21 Aug Icelandair direct
15 Aug - 22 Aug Icelandair direct
16 Aug - 23 Aug Icelandair direct
22 Aug - 29 Aug Icelandair direct
18 Aug - 25 Aug Icelandair direct
19 Aug - 26 Aug Icelandair direct
27 Aug - 03 Sep Icelandair direct
28 Aug - 04 Sep Icelandair direct
29 Aug - 05 Sep Icelandair direct
26 Aug - 02 Sep Icelandair direct
25 Aug - 01 Sep United
30 Aug - 06 Sep Delta
30 Aug - 06 Sep Icelandair direct
31 Aug - 07 Sep Icelandair direct
25 Aug - 01 Sep Icelandair direct

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

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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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