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

Return flights

05 May - 12 May	Virgin Atlantic
06 May - 13 May	KLM
04 May - 12 May	Air France
11 May - 18 May	Air France
15 May - 22 May	Air France
16 May - 23 May	KLM
19 May - 26 May	KLM
14 May - 23 May	Delta
20 May - 27 May	Air France
30 May - 06 Jun	Southwest Airlines
31 May - 07 Jun	Southwest Airlines
28 May - 04 Jun	Southwest Airlines
29 May - 05 Jun	Southwest Airlines
26 May - 02 Jun	Air France
27 May - 03 Jun	KLM

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

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Cheapest return flights from Chicago to Keflavik in May from 604€

Return flights