The cheapest Istanbul to Seoul return flight on the radar right now is €427, flying with China Southern via one or more connections. It covers departures in December 2026, and every dated link below opens that exact IST–ICN search on Skyscanner. That is roughly 12% below the €484 this route usually costs. Across 87 recorded checks it has ranged between €399 and €772. Our sampling points to December 2026 as the cheapest month to fly Istanbul to Seoul.
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 Istanbul? We track 61 other departure cities for Seoul, listed at the foot of this page.
Fares move quickly. If this Istanbul to Seoul 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.