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

Return flights

22 Sep - 06 Oct	Aeromexico
25 Sep - 01 Oct	Aeromexico
20 Sep - 23 Sep	Viva
27 Sep - 05 Oct	Aeromexico
20 Sep - 01 Oct	Viva
12 Sep - 24 Sep	Viva
25 Sep - 02 Oct	Aeromexico
11 Sep - 16 Sep	Volaris
11 Sep - 24 Sep	Volaris
13 Sep - 23 Sep	Viva
20 Sep - 27 Sep	Volaris
20 Sep - 30 Sep	Aeromexico
09 Sep - 18 Sep	Viva
08 Sep - 15 Sep	Viva
11 Sep - 20 Sep	Volaris
27 Sep - 18 Oct	Delta

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

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

Cheapest return flights from Mexico City to Keflavik in September from $620

Return flights