Barbara Ann Brennan was born on 19 February 1939 in Wisconsin. She trained as a physicist, earning a master's degree in atmospheric physics, and worked for a period at NASA's Goddard Space Flight Center, a scientific research background that set her apart from most other figures in the modern energy healing movement and that she drew on explicitly, using the vocabulary of fields and energy from physics to frame her later esoteric work. During the 1970s she left conventional science to pursue what she described as her own developing clairvoyant perception of a subtle energy field surrounding the human body, training in various bodywork, counseling and healing modalities along the way.
She founded the Barbara Brennan School of Healing to teach her integrated system of perception and hands on healing work in a structured, multi year training program, building an institution that trained practitioners internationally over several decades. She continued writing, teaching and directing the School until her death on 3 October 2022, at eighty three.
Her transition from a NASA research career to full time energy healing work in the 1970s placed her at the intersection of the American human potential movement and the era's broader popular interest in bridging physics and consciousness, a pairing several other authors of the period also explored but few carried as far into a structured, credentialing training institution as Brennan eventually built with her School.