AirHint found the following cheapest return flights from London (LCY) to Bucharest (OTP) in September 2025 (see full year).

Return flights

29 Sep - 07 Oct	KLM
09 Sep - 16 Sep	KLM
18 Sep - 23 Sep	Lufthansa
22 Sep - 29 Sep	KLM
02 Sep - 09 Sep	Lufthansa
04 Sep - 07 Oct	Lufthansa
04 Sep - 01 Oct	Lufthansa
25 Sep - 01 Oct	Lufthansa
02 Sep - 17 Sep	Lufthansa
19 Sep - 23 Sep	SWISS
25 Sep - 06 Oct	Lufthansa
15 Sep - 18 Sep	Lufthansa
01 Sep - 09 Sep	Lufthansa
16 Sep - 18 Sep	Lufthansa
16 Sep - 29 Sep	Lufthansa
25 Sep - 03 Oct	Lufthansa
26 Sep - 01 Oct	SWISS
27 Sep - 07 Oct	KLM
26 Sep - 03 Oct	KLM
27 Sep - 01 Oct	KLM

Also check the deals for one-way flights from London to Bucharest 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 London to Bucharest in September from $259

Return flights