Siani is a Welsh form related to Jane or Sian, ultimately from Hebrew Yohanan meaning God is gracious.
Siani is the Welsh diminutive and pet form of Siân, which is itself the Welsh adaptation of the English Jane and the French Jeanne — all ultimately descending from the Hebrew Yohannah, meaning "God is gracious" or "Yahweh has shown favor." This ancient theological thread runs from the Hebrew scriptures through Latin, through medieval French, through English, and finally into Welsh, where it transformed phonetically into something altogether its own. Wales has a long tradition of taking pan-European names and domesticating them through Welsh phonology, giving rise to forms that feel both familiar and distinctly Celtic.
Siân and its diminutive Siani have been affectionate staples of Welsh-speaking communities for centuries, carrying the warmth of intimacy — in Welsh culture, the "-i" ending frequently functions as a term of endearment, much like the "-ie" or "-y" suffix in English. Notable Welsh bearers of the root name include actress Siân Phillips, celebrated for her portrayal of Livia in the BBC adaptation of "I, Claudius," lending the name a gravity and intelligence in the broader cultural imagination. In recent decades, as Welsh language revitalization movements have strengthened and parents across the anglophone world have grown more interested in Celtic and minority-language names, Siani has begun appearing beyond Wales.
It offers a gentle, melodic sound — typically pronounced "SHAH-nee" — that travels well across linguistic borders. For families with Welsh heritage, it is an act of cultural preservation; for others, it is simply a beautiful name with deep roots in a living ancient tradition.