Cheapest return flights from San Francisco to Keflavik in September from $602

AirHint found the following cheapest return flights from San Francisco (SFO) to Keflavik (KEF) in September 2025 (see full year).

Return flights

23 Sep - 30 Sep Alaska Airlines
29 Sep - 06 Oct Flair Airlines
04 Sep - 08 Sep Alaska Airlines
07 Sep - 01 Oct Sun Country Airlines
04 Sep - 11 Sep Hawaiian Airlines
06 Sep - 13 Sep Alaska Airlines
09 Sep - 16 Sep Flair Airlines
05 Sep - 07 Sep jetBlue
20 Sep - 28 Sep Alaska Airlines
10 Sep - 17 Sep Air Canada
25 Sep - 02 Oct Frontier Airlines
16 Sep - 23 Sep Flair Airlines
24 Sep - 01 Oct Alaska Airlines
27 Sep - 04 Oct Hawaiian Airlines
13 Sep - 20 Sep Hawaiian Airlines
28 Sep - 05 Oct Hawaiian Airlines
26 Sep - 03 Oct Frontier Airlines

Also check the deals for one-way flights from San Francisco to Keflavik in September.

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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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