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

Return flights

27 Sep - 06 Oct	Air Canada
29 Sep - 20 Oct	Air Canada
29 Sep - 16 Oct	Air Canada
29 Sep - 08 Oct	Lufthansa
27 Sep - 02 Oct	Air Canada
29 Sep - 10 Oct	Lufthansa
29 Sep - 11 Oct	Air Canada
28 Sep - 12 Oct	American Airlines
27 Sep - 05 Oct	Air Canada
27 Sep - 04 Oct	Air Canada
27 Sep - 28 Sep	Air Canada
27 Sep - 30 Sep	American Airlines
25 Sep - 28 Sep	Lufthansa
26 Sep - 30 Sep	Finnair
25 Sep - 29 Sep	Air Canada
22 Sep - 28 Sep	SWISS
23 Sep - 30 Sep	Avianca
23 Sep - 27 Sep	Avianca
22 Sep - 25 Sep	Avianca
26 Sep - 29 Sep	Avianca

Also check the deals for one-way flights from London to Cancun 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.

Book a cheap hotel in Cancun

Cheap car rent in Cancun

Cheapest return flights from London to Cancun in September from 505€

Return flights