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

Return flights

12 May - 19 May	Lufthansa
06 May - 10 May	SWISS
06 May - 18 May	SWISS
06 May - 11 May	SWISS
12 May - 18 May	Lufthansa
11 May - 18 May	SWISS
28 May - 04 Jun	Lufthansa
01 May - 08 May	Delta
16 May - 26 May	SWISS
01 May - 31 May	SWISS
13 May - 20 May	British Airways
27 May - 09 Jun	SWISS
22 May - 07 Jun	SWISS
25 May - 16 Jun	Lufthansa
25 May - 18 Jun	Lufthansa

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 $561

Return flights