AirHint found the following cheapest return flights from London (LHR) to Boston (BOS) in May 2026 (see full year).

Return flights

12 May - 19 May	SWISS
14 May - 21 May	SWISS
16 May - 26 May	SWISS
08 May - 22 May	SWISS
01 May - 31 May	Lufthansa
12 May - 18 May	SWISS
20 May - 03 Jun	SWISS
16 May - 23 May	SWISS
28 May - 02 Jun	SWISS
20 May - 30 May	SWISS
07 May - 23 May	Air Canada
20 May - 27 May	SWISS
17 May - 01 Jun	Air Canada
21 May - 04 Jun	Air Canada
29 May - 08 Jun	Lufthansa
22 May - 02 Jun	Air Canada
21 May - 04 Jun	British Airways	direct
17 May - 01 Jun	British Airways	direct
29 May - 08 Jun	British Airways	direct

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

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 London to Boston in May from $475

Return flights