Cheapest return flights from Seattle to Keflavik in May from $523

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 May 2025 (see full year).

Return flights

09 May - 13 May Icelandair direct
24 May - 31 May Icelandair direct
06 May - 20 May Icelandair direct
26 May - 02 Jun Alaska Airlines
15 May - 22 May Icelandair direct
25 May - 31 May Icelandair direct
16 May - 23 May Icelandair direct
04 May - 11 May Icelandair direct
06 May - 13 May Icelandair direct
09 May - 16 May Icelandair direct
02 May - 09 May Icelandair direct
26 May - 02 Jun Icelandair direct
27 May - 03 Jun Icelandair direct
30 May - 06 Jun Icelandair direct
31 May - 07 Jun Icelandair direct
28 May - 04 Jun Icelandair direct
29 May - 05 Jun Icelandair direct
25 May - 01 Jun KLM
23 May - 01 Jun Delta
25 May - 01 Jun Icelandair direct

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

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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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