AirHint found the following cheapest return flights from London (LHR) to Buenos Aires (AEP) in December 2025 (see full year).

Return flights

02 Dec - 11 Dec	Avianca
02 Dec - 10 Dec	Avianca
01 Dec - 10 Dec	Avianca
09 Dec - 14 Dec	Air Canada
07 Dec - 15 Jan	Air Canada
03 Dec - 04 Dec	SWISS
05 Dec - 18 Jan	Air Canada
05 Dec - 12 Dec	LATAM Airlines Group
04 Dec - 10 Dec	LATAM Airlines Group
27 Dec - 27 Jan	LATAM Airlines Group
29 Dec - 30 Jan	LATAM Airlines Group
06 Dec - 11 Dec	LATAM Airlines Group
26 Dec - 30 Jan	LATAM Airlines Group
25 Dec - 30 Jan	LATAM Airlines Group
11 Dec - 18 Dec	Vueling Airlines
01 Dec - 20 Dec	Avianca
27 Dec - 30 Jan	LATAM Airlines Group
02 Dec - 30 Jan	LATAM Airlines Group
27 Dec - 23 Jan	LATAM Airlines Group
10 Dec - 13 Jan	Air Canada

Also check the deals for one-way flights from London to Buenos Aires 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 Buenos Aires in December from 960€

Return flights