The cheapest Barcelona to San Juan return flight on the radar right now is €694, flying with Iberia via one or more connections. It covers departures in November 2026, and every dated link below opens that exact BCN–SJU search on Skyscanner. Across 76 recorded checks it has ranged between €577 and €1,422. Our sampling points to November 2026 as the cheapest month to fly Barcelona to San Juan.
Prices are re-checked against Skyscanner automatically, and every one shows when it was last confirmed, so nothing here is older than it looks. Not flying from Barcelona? We track 53 other departure cities for San Juan, listed at the foot of this page.
Prices like this tend to vanish fast. If it has gone when you look, try the days either side of the dates above, since Barcelona to San Juan is often still worth booking within a day or two of the fare we found.