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

Return flights

04 May - 16 May	TAP
03 May - 15 May	American Airlines
04 May - 23 May	TAP
17 May - 04 Jun	SWISS
01 May - 20 May	Lufthansa
27 May - 03 Jun	Air Canada
28 May - 04 Jun	SWISS
20 May - 31 May	Lufthansa
29 May - 05 Jun	Iberia
29 May - 04 Jun	Iberia
27 May - 14 Jun	Azores Airlines
27 May - 14 Jun	TAP	direct
04 May - 23 May	TAP	direct
31 May - 06 Jun	British Airways
27 May - 03 Jun	TAP	direct
30 May - 06 Jun	TAP	direct
20 May - 31 May	TAP	direct
03 May - 23 May	Air France

Also check the deals for one-way flights from Boston to Porto 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 Boston to Porto in May from $406

Return flights