Cheapest return flights from Denver to Keflavik in September from $419

Best time to book flights for Denver (DEN) to Keflavik (KEF) flights at AirHint

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

Return flights

27 Sep - 06 Oct Icelandair direct
11 Sep - 07 Oct Icelandair direct
21 Sep - 26 Sep Icelandair direct
03 Sep - 24 Sep Icelandair direct
24 Sep - 29 Sep Icelandair direct
04 Sep - 21 Sep KLM
04 Sep - 21 Sep Icelandair direct
19 Sep - 21 Sep Icelandair direct
05 Sep - 12 Sep Frontier Airlines
05 Sep - 12 Sep Icelandair direct

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

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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