AirHint found the following cheapest return flights from Basel (BSL) to Kos (KGS) in September 2025 (see full year).

Return flights

10 Sep - 17 Sep	easyJet
10 Sep - 21 Sep	easyJet
03 Sep - 10 Sep	easyJet	direct
14 Sep - 17 Sep	easyJet
15 Sep - 21 Sep	easyJet
01 Sep - 07 Sep	easyJet
21 Sep - 28 Sep	easyJet
14 Sep - 28 Sep	Wizz Air
14 Sep - 01 Oct	Wizz Air
10 Sep - 17 Sep	easyJet	direct
14 Sep - 21 Sep	Wizz Air
14 Sep - 01 Oct	easyJet	direct
28 Sep - 05 Oct	easyJet
28 Sep - 05 Oct	easyJet	direct

Also check the deals for one-way flights from Basel to Kos 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 Kos

Cheap car rent in Kos

Cheapest return flights from Basel to Kos in September from 139€

Return flights