Sian Winstanley was born in Cardiff where she promptly followed her father into local amateur dramatics where she first appeared as an urchin in "My Fair Lady". Her solo career began at an early age with a rendition of "We're walking in the air" in the school nativity play, but she eventually graduated from the Royal Welsh College of Music & Drama with a 1st for her B.Mus and a distinction for her M.Mus.

Sian has since performed with Garsington Opera (Anne Trulove and chorus in The Rake's Progress, Clorinda in Rossini's Cenerentola, and chorus in Fidelio), Opera A La Carte (choirboy and shepherdboy in Tosca), Bampton Classical Opera, Opera'r Ddraig (Countess in The Marriage of Figaro), Dumbworld (various roles; Postcards From Dumbworld; Irvine), Music Theatre Wales (lead child in The Roswell Incident by Hardy) and The Gate (lead child in The Raven King by Burtch). She is a regular soloist with the BBC National Chorus of Wales with whom she has featured on Proms in the Park, BBC Radio Three, BBC Radio Wales, French radio and commercial recordings. She has sung at festivals from Belfast to Paris and with orchestras and choirs across Britain including the BBC National Orchestra of Wales, the Bournemouth Symphony Orchestra, the City if Birmingham Symphony Orchestra and Chorus, the Orchestra of the Age of Enlightenment and the Welsh Baroque Orchestra.

Sian currently divides her time between her busy concert schedule and teaching across Wales (including at the Royal Welsh College of Music & Drama) and in Bristol; she also gives voice and character workshops.