Mary Greer is an author and teacher specializing in methods of self-exploration and transformation. A Grandmaster of the American Tarot Association, she is a member of numerous Tarot organizations, and is featured at Tarot conferences and symposia in the United States and abroad.

Mary also has a wide following in the women's and pagan communities for her work in women's spirituality and magic. A Priestess-Hierophant in the Fellowship of Isis, she is the founder of the Iseum of Isis Aurea.

Mary has studied and practiced Tarot and astrology for over 34 years. Her teaching experience includes eleven years at New College of California, as well as at many workshops, conferences, and classes. She is the founder and director of the learning center T.A.R.O.T. (Tools and Rites of Transformation).

Her books include Tarot for Your Self: A Workbook for Personal Transformation (1984); Tarot Constellations: Patterns of Personal Destiny (1987); Tarot Mirrors: Reflections of Personal Meaning (1988); The Essence of Magic: Tarot, Ritual, and Aromatherapy (1993); Women of the Golden Dawn: Rebels and Priestesses (1995); and Aromatherapy: Healing for the Body and Soul (1998), with Kathi Keville.