Cyril Fagan (born Dublin, Ireland, May 22, 1896, died Tucson, Arizona, United States, January 5, 1970) was an Irish astrologer, Generally considered the father - alongside Donald A. Bradley, the mother, of the western sidereal astrology.^[1] He is the creator with American astrologer Bradley of the Fagan-Bradley Ayanamsha.^[2]

His books include:

• Astrological Origins, Zodiacs Old and New St. Paul, Minn.: Llewellyn Publications, 1971.
• Fixed Zodiac Ephemeris for 1948. Washington, D.C.: National Astrological Library, 1948.
• A Primer of the Sidereal Zodiac
• Zodiacs Old and New. Los Angeles: Llewellyn Publications, 1950.