Cheapest one-way flights from Seattle to Keflavik in August from $257

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

One-Way flights

25 Aug Frontier Airlines
13 Aug WestJet
21 Aug Air Canada
04 Aug Sun Country Airlines
25 Aug Icelandair direct
21 Aug Icelandair direct
22 Aug Icelandair direct
23 Aug Icelandair direct
26 Aug Icelandair direct
27 Aug Icelandair direct

Also check the deals for return flights from Seattle to Keflavik in August.

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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