The cheapest Porto to Sydney return flight on the radar right now is €1,339, flying with Austrian Airlines + Lufthansa via one or more connections. It covers departures in April 2027, and every dated link below opens that exact OPO–SYD search on Skyscanner. The price we usually record on this route is €1,280. Across 77 recorded checks it has ranged between €891 and €1,403. Our sampling points to April 2027 as the cheapest month to fly Porto to Sydney.
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 Porto? We track 56 other departure cities for Sydney, listed at the foot of this page.
Fares move quickly. If this Porto to Sydney 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.