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

Return flights

20 Dec - 27 Dec	Ryanair	direct
22 Dec - 27 Dec	Ryanair	direct
05 Dec - 08 Dec	Austrian Airlines
11 Dec - 14 Dec	Austrian Airlines
30 Dec - 02 Jan	Austrian Airlines

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

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 December from $78

Return flights