Hugh Mackay (June 9, 1890 - July 9, 1943) was one of Scotland's magical stalwarts who came to magical prominence during the 1920s when he began his many publishing activities and founding the Council of Nine.
Mackay published under his own name and the pseudonyms of Sirius and Dr. S. Holmes. Mackay's first publishing venture was a periodical Magical Criticisms as Sirius. After only five issues, he quickly followed that with The Magical Observer (Starting in June, 1923 for two years, with 24 issues in all).
In 1927, he formed the Council of Nine for the purpose of Magical Research and discussion of other subjects relative to the Art of Magic.