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

Return flights

01 Dec - 11 Dec	Iberia	direct
02 Dec - 25 Dec	Iberia	direct
01 Dec - 25 Dec	Iberia	direct
03 Dec - 09 Dec	Iberia
03 Dec - 10 Dec	Iberia
03 Dec - 11 Dec	Iberia
05 Dec - 09 Dec	TAP
05 Dec - 12 Dec	Iberia	direct
05 Dec - 09 Dec	Iberia	direct
09 Dec - 16 Dec	Iberia
09 Dec - 26 Jan	TAP
11 Dec - 26 Jan	TAP
30 Dec - 24 Jan	Iberia
31 Dec - 08 Jan	British Airways
11 Dec - 19 Jan	TAP
30 Dec - 24 Jan	Iberia	direct
15 Dec - 17 Jan	Iberia
27 Dec - 10 Jan	Iberia
30 Dec - 07 Jan	Iberia
15 Dec - 10 Jan	Aer Lingus

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

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 December from $300

Return flights