The Siuni or Siwni dynasty (Old Armenian: Սիւնի) was an ancient Armenian princely (nakharar) dynasty which ruled the province of Siwnikʻ, with which the dynasty shared its name. They were one of the most important and powerful princely houses in antique and early medieval Armenia.
The Siwnis were said to be descendants of Sisak, one of the descendants of Hayk, the legendary patriarch of the Armenians. According to Robert H. Hewsen, the Siwnis were of non-Armenian origin. They were recognized as the hereditary rulers of Siwnikʻ with the division of Greater Armenia into provinces (ashkharhs) under Artaxias I in the second century BCE, although they may have been the local ruling dynasty even before that. The Siwnis were the most powerful princely house in the Kingdom of Armenia. According to the Zōranamak, a military register which listed the military obligations of each of the great noble houses, the Siwnis were supposed to raise a cavalry force of 19,400. They were honored with numerous gifts and privileges by the Armenian kings for their services, including the privilege of occupying the first seat next to the king at the royal banquet table.
