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

Return flights

03 Sep - 07 Sep	TAP
15 Sep - 07 Oct	TAP
10 Sep - 15 Sep	Iberia For Level
13 Sep - 20 Sep	Iberia For Level
03 Sep - 09 Sep	TAP
13 Sep - 29 Sep	Iberia For Level
11 Sep - 15 Sep	Lufthansa
10 Sep - 24 Sep	Lufthansa
01 Sep - 06 Sep	Lufthansa
01 Sep - 16 Sep	Lufthansa
02 Sep - 12 Sep	Lufthansa
05 Sep - 11 Oct	Aer Lingus
26 Sep - 04 Oct	Aer Lingus
23 Sep - 01 Oct	United
04 Sep - 09 Oct	Aer Lingus
26 Sep - 05 Oct	Aer Lingus
25 Sep - 02 Oct	British Airways	direct
28 Sep - 05 Oct	British Airways	direct
05 Sep - 11 Oct	Iberia	direct
04 Sep - 09 Oct	British Airways	direct

Also check the deals for one-way flights from Boston 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.

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Cheapest return flights from Boston to London in September from 370€

Return flights