AirHint found the following cheapest return flights from Portland (PDX) to Keflavik (KEF) in May 2026 (see full year).

Return flights

22 May - 31 May	Icelandair	direct
03 May - 11 May	Delta
04 May - 12 May	KLM
10 May - 18 May	Delta
11 May - 19 May	KLM
12 May - 20 May	Delta
09 May - 17 May	KLM
12 May - 20 May	Icelandair	direct
18 May - 26 May	Icelandair	direct
19 May - 27 May	Icelandair	direct
27 May - 04 Jun	Icelandair	direct
29 May - 06 Jun	Icelandair	direct
24 May - 01 Jun	KLM
25 May - 02 Jun	Delta
26 May - 03 Jun	Delta
28 May - 05 Jun	KLM
30 May - 07 Jun	KLM
31 May - 08 Jun	KLM
30 May - 07 Jun	Icelandair	direct
26 May - 03 Jun	Icelandair	direct

Also check the deals for one-way flights from Portland to Keflavik in May.

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 Portland to Keflavik in May from $537

Return flights