AirHint found the following cheapest return flights from Klagenfurt (KLU) to London (STN) in September 2025 (see full year).

Return flights

25 Sep - 02 Oct	Ryanair	direct
25 Sep - 09 Oct	Ryanair	direct
25 Sep - 12 Oct	Ryanair	direct
25 Sep - 16 Oct	Ryanair	direct
28 Sep - 19 Oct	Ryanair	direct
28 Sep - 09 Oct	Ryanair	direct
28 Sep - 12 Oct	Ryanair	direct
28 Sep - 16 Oct	Ryanair	direct
25 Sep - 28 Sep	Ryanair	direct
25 Sep - 05 Oct	Ryanair	direct
28 Sep - 30 Sep	Ryanair
24 Sep - 28 Sep	Ryanair
25 Sep - 26 Sep	Ryanair
23 Sep - 28 Sep	Ryanair
26 Sep - 28 Sep	Ryanair
26 Sep - 03 Oct	Ryanair
22 Sep - 24 Sep	Eurowings
25 Sep - 25 Sep	Austrian Airlines

Also check the deals for one-way flights from Klagenfurt to London 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.

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Cheapest return flights from Klagenfurt to London in September from 38€

Return flights