Cheapest return flights from Seattle to Keflavik in December from 339€

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

Return flights

01 Dec - 08 Dec Icelandair direct
02 Dec - 09 Dec Icelandair direct
03 Dec - 10 Dec Icelandair direct
04 Dec - 11 Dec Icelandair direct
05 Dec - 12 Dec Icelandair direct
07 Dec - 14 Dec Icelandair direct
08 Dec - 15 Dec Icelandair direct
09 Dec - 16 Dec Icelandair direct
10 Dec - 17 Dec Icelandair direct
11 Dec - 18 Dec Icelandair direct
29 Dec - 05 Jan Icelandair direct
30 Dec - 06 Jan Icelandair direct
28 Dec - 03 Jan Icelandair direct
25 Dec - 01 Jan Icelandair direct
26 Dec - 02 Jan Icelandair direct
27 Dec - 03 Jan Icelandair direct
28 Dec - 04 Jan Icelandair direct

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

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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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