The cheapest Barcelona to Boston return flight on the radar right now is €435, flying with Aer Lingus via one or more connections. It covers departures in December 2026, and every dated link below opens that exact BCN–BOS search on Skyscanner. The price we usually record on this route is €463. Across 64 recorded checks it has ranged between €328 and €1,228. Our sampling points to December 2026 as the cheapest month to fly Barcelona to Boston.
Every fare here is re-confirmed against Skyscanner automatically, and each one is stamped with the moment it was last checked, so you can see how fresh it is instead of taking it on trust. Not flying from Barcelona? We track 52 other departure cities for Boston, listed at the foot of this page.
Fares move quickly. If this Barcelona to Boston price has gone by the time you search, shift the dates a day or two either side, because the same route is often still cheap just next door.