Cheapest return flights from Seattle to Keflavik in August from $530

Best time to book flights for Seattle (SEA) to Keflavik (KEF) flights at AirHint

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

Return flights

09 Aug - 15 Aug Icelandair direct
28 Aug - 07 Sep Icelandair direct
31 Aug - 08 Sep Icelandair direct
06 Aug - 13 Aug Icelandair direct
11 Aug - 18 Aug Icelandair direct
21 Aug - 28 Aug Icelandair direct
31 Aug - 07 Sep Icelandair direct
28 Aug - 01 Sep Icelandair direct
08 Aug - 17 Aug Icelandair direct
30 Aug - 06 Sep Icelandair direct
01 Aug - 08 Aug 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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