Cheapest return flights from London to Boston in September from $430

Best time to book flights for London (LHR) to Boston (BOS) flights at AirHint

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

Return flights

23 Sep - 15 Oct TAP
27 Sep - 15 Oct TAP
22 Sep - 15 Oct TAP
27 Sep - 12 Oct TAP
29 Sep - 12 Oct TAP
30 Sep - 13 Oct TAP
28 Sep - 14 Oct TAP
29 Sep - 14 Oct TAP
29 Sep - 03 Oct SWISS
07 Sep - 17 Sep SWISS
02 Sep - 30 Sep SWISS
18 Sep - 27 Sep SWISS
11 Sep - 24 Sep SWISS
18 Sep - 23 Sep SWISS
10 Sep - 24 Sep SWISS
11 Sep - 17 Sep SWISS
10 Sep - 22 Sep SWISS
18 Sep - 22 Sep SWISS
11 Sep - 25 Sep SWISS
23 Sep - 02 Oct SWISS

Also check the deals for one-way flights from London to Boston in September.

Skyscanner

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 Boston

Cheap car rent in Boston