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

Return flights

10 Sep - 29 Sep	Air India
08 Sep - 15 Sep	Air India
11 Sep - 18 Sep	Air India
07 Sep - 30 Sep	Air India
14 Sep - 25 Sep	Air India
10 Sep - 22 Sep	Air India
11 Sep - 02 Oct	Air India
18 Sep - 08 Oct	Air India
28 Sep - 20 Oct	Air India
29 Sep - 14 Oct	Air India
09 Sep - 25 Sep	Air India
29 Sep - 15 Oct	Air India
08 Sep - 21 Sep	Air India
26 Sep - 08 Oct	Air India
27 Sep - 07 Oct	Air India
25 Sep - 10 Oct	Etihad Airways
08 Sep - 18 Sep	Air India
08 Sep - 17 Sep	Air India
15 Sep - 08 Oct	Air India
27 Sep - 11 Oct	Air India

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

Cheap car rent in London

Cheapest return flights from Kolkata to London in September from 459€

Return flights