William Wynn Westcott (17 December 1848 – 30 July 1925) was a coroner, ceremonial magician, Theosophist and Freemason born in Leamington, Warwickshire, England. He was a Supreme Magus (chief) of the S.R.I.A and went on to co-found the Golden Dawn.
He was a doctor of medicine.
In 1871 he became active in Freemasonry where he become Master of his home Lodge three years later and also the Quatuor Coronati research lodge (Master 1893–94).
In 1879 he moved to Hendon. In 1880 he began studying the Kabbalah and joined Societas Rosicruciana in Anglia. In 1882 he met Samuel Liddell Mathers.
Societas Rosicruciana in Anglia
Main article: Societas Rosicruciana in Anglia
Westcott became chief of the SRIA with the death of William Robert Woodman.
The Golden Dawn
Main article: Hermetic Order of the Golden Dawn
Wescott co-founded the Hermetic Order of the Golden Dawn with Samuel Liddell MacGregor Mathers and William Robert Woodman in 1887, using the motto V.H. Frater Sapere Aude.
Around this time, he was also active in the Theosophical Society, where he founded in 1891 The Adelphi Lodge in London WC.
In 1896, he abandoned public involvement with the Golden Dawn due to pressure regarding his job as a Crown Coroner, with which it was seen as an unseemly association. He continued to head the S.R.I.A. and later was involved with the Golden Dawn breakaway Stella Matutina.
He retired as a coroner after 1910, emigrated to South Africa in 1918, and died in Durban in 1925.