AirHint found the following cheapest return flights from London (LHR) to Mexico City (MEX) in September 2025 (see full year).

Return flights

11 Sep - 21 Oct	British Airways
13 Sep - 28 Sep	Lufthansa
13 Sep - 30 Sep	Lufthansa
13 Sep - 23 Sep	Lufthansa
05 Sep - 15 Sep	Lufthansa
11 Sep - 24 Sep	Lufthansa
15 Sep - 23 Sep	Lufthansa
09 Sep - 26 Sep	Lufthansa
09 Sep - 23 Sep	Lufthansa
11 Sep - 25 Sep	Lufthansa
12 Sep - 23 Sep	Lufthansa
11 Sep - 06 Oct	Lufthansa
05 Sep - 11 Oct	Lufthansa
15 Sep - 15 Oct	Lufthansa
16 Sep - 14 Oct	Lufthansa
29 Sep - 06 Oct	Air Canada
25 Sep - 02 Oct	Air Canada
25 Sep - 04 Oct	Air Canada
19 Sep - 03 Oct	Air Canada
19 Sep - 06 Oct	Air Canada

Also check the deals for one-way flights from London to Mexico City 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 Mexico City in September from $738

Return flights