AirHint found the following cheapest return flights from Belfast (BFS) to London (LTN) in September 2025 (see full year).

Return flights

14 Sep - 27 Oct	easyJet	direct
21 Sep - 30 Sep	easyJet	direct
14 Sep - 21 Sep	easyJet	direct
15 Sep - 20 Sep	easyJet	direct
28 Sep - 29 Sep	easyJet	direct
25 Sep - 29 Sep	easyJet	direct
13 Sep - 14 Sep	easyJet	direct
04 Sep - 13 Sep	easyJet	direct
04 Sep - 09 Sep	easyJet
05 Sep - 13 Sep	easyJet	direct
05 Sep - 09 Sep	easyJet

Also check the deals for one-way flights from Belfast 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 Belfast to London in September from $45

Return flights