Cheapest return flights from Washington to Keflavik in September from $525

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

Return flights

09 Sep - 16 Sep Air Canada
03 Sep - 10 Sep Air Canada
03 Sep - 24 Sep Delta
04 Sep - 12 Sep Air Canada
05 Sep - 12 Sep Air Canada
11 Sep - 15 Sep Air Canada
12 Sep - 20 Sep Air Canada
06 Sep - 13 Sep Air Canada
15 Sep - 22 Sep United
26 Sep - 29 Sep Scandinavian Airlines
29 Sep - 04 Oct Icelandair
13 Sep - 10 Oct Icelandair

Also check the deals for one-way flights from Washington 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.

Book a cheap hotel in Keflavik

Cheap car rent in Keflavik

Feel free to contact us with any feedback or request another flight research.