The cheapest Tallinn to San Juan return flight on the radar right now is €1,020, flying with Finnair via one or more connections. It covers departures in March 2027, and every dated link below opens that exact TLL–SJU search on Skyscanner. The price we usually record on this route is €754. Across 18 recorded checks it has ranged between €707 and €1,023. Our sampling points to March 2027 as the cheapest month to fly Tallinn 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 Tallinn? We track 52 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 Tallinn to San Juan is often still worth booking within a day or two of the fare we found.