The cheapest Porto to Saint Lucia return flight on the radar right now is €728, flying with British Airways via one or more connections. It covers departures in December 2026, and every dated link below opens that exact OPO–UVF search on Skyscanner. The price we usually record on this route is €768. Across 15 recorded checks it has ranged between €712 and €793. Our sampling points to December 2026 as the cheapest month to fly Porto to Saint Lucia.
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 Porto? We track 41 other departure cities for Saint Lucia, 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 Porto to Saint Lucia is often still worth booking within a day or two of the fare we found.