AirHint found the following cheapest return flights from Boston (BOS) to Madrid (MAD) in August 2025 (see full year).

Return flights

25 Aug - 10 Sep	Lufthansa
21 Aug - 13 Sep	Air Canada
19 Aug - 03 Sep	British Airways	direct
19 Aug - 27 Aug	British Airways
16 Aug - 06 Sep	British Airways	direct
20 Aug - 27 Aug	Air Canada
20 Aug - 28 Aug	Air Canada
23 Aug - 13 Sep	Air Canada
22 Aug - 03 Sep	United
22 Aug - 13 Sep	United
23 Aug - 03 Sep	SWISS
21 Aug - 25 Aug	United
19 Aug - 26 Aug	Lufthansa
17 Aug - 25 Aug	British Airways
18 Aug - 25 Aug	British Airways
19 Aug - 25 Aug	British Airways
22 Aug - 25 Aug	United
25 Aug - 08 Sep	Lufthansa
16 Aug - 23 Aug	Air Canada
31 Aug - 07 Sep	Iberia

Also check the deals for one-way flights from Boston to Madrid in August.

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 Madrid in August from 334€

Return flights