Ætsæg Din or Uatsdin (Ossetian: Æцæг Дин, Уацдин, literally "Exact Faith", "Right Faith", "Holy Faith") is the modern organised revival of Ossetian ethnic religion (see Ossetian mythology), emerging since the 1980s.
The Ossetians are an Eastern Iranic people of Alan-Scythian stock inhabiting a homeland in the Caucasus, now split between two states: the republic of North Ossetia–Alania within Russia, and the neighbouring, partly recognised state of South Ossetia (within Georgia).
In the Ossetian case, certain traditions of folk religion had survived with unbroken continuity, and were revived in rural areas. This contrasts, and interacts, with an urban and more intellectual movement which elaborated a systematic revival religion to overcome the crisis of identity of the Ossetian people, based in ethnic nationalism and opposition to both Russian and Georgian Orthodox Christianity, perceived as foreign, as well as the Islam professed by the neighboring Turkic and Caucasian ethnic groups and among a small minority of Ossetians.
The Etseg Din movement is active both in North and South Ossetia. Whilst there are no figures about religious demographics for South Ossetia, in North Ossetia–Alania about 29% of the population adheres ethnic or folk religion according to 2012 survey statistics.