AirHint found the following cheapest return flights from London (LCY) to Brussels (BRU) in December 2025 (see full year).

Return flights

04 Dec - 08 Dec	KLM
24 Dec - 31 Dec	KLM
03 Dec - 07 Dec	KLM
03 Dec - 14 Dec	KLM
04 Dec - 14 Dec	KLM
04 Dec - 07 Dec	KLM
02 Dec - 07 Dec	KLM
17 Dec - 24 Dec	KLM
30 Dec - 02 Jan	KLM
29 Dec - 03 Jan	KLM
29 Dec - 01 Jan	KLM
30 Dec - 06 Jan	KLM
31 Dec - 03 Jan	KLM
30 Dec - 03 Jan	KLM
17 Dec - 12 Jan	KLM
04 Dec - 11 Dec	ITA Airways
09 Dec - 16 Dec	KLM
26 Dec - 05 Jan	KLM
23 Dec - 03 Jan	KLM
22 Dec - 02 Jan	KLM

Also check the deals for one-way flights from London to Brussels 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 London to Brussels in December from 210€

Return flights