Toni Packer was born in Berlin, Germany in 1927. Her family was Lutheran in name only, as they endeavored not to divulge the fact that her mother was of Jewish decent. It was in her childhood, growing up amidst the turmoil of Nazi Germany, that Packer first developed mistrust for authority. The family eventually made a move to Switzerland, where she married her husband Kyle Packer in 1950. The pair moved to New York near the State University of New York at Buffalo, where Kyle came to earn a degree in psychology. She began reading the pioneering works about Zen Buddhism by Alan Watts, D. T. Suzuki and Philip Kapleau. It was the latter which had the greatest impact on her, and she soon joined the nearby Rochester Zen Center with her husband. Throughout the 1970s she accepted minor teaching positions at Rochester, and in 1981 she ran the center for an extended period in Kapleau's absence. During this time she instituted many changes in the practice there and discontinued wearing the rakusu that normally distinguishes teachers from students. Packer left the Center shortly after Kapleau's return and ceased practicing Buddhism, opening the Genesee Valley Zen Center that same year. In 1986 the center relocated and changed its name, dropping the word Zen to become the Springwater Center for Meditative Inquiry and Retreats in Springwater, New York. The word "Zen" was eliminated from the name due to the elimination of many Japanese and Buddhist traditions from their work. Through stripped of rituals, Packer still finds the practice of zazen to be useful.

Packer's teaching has been described as "...a Zen teacher minus the 'Zen' and minus the 'teacher,'" emphasizing the importance of meditative inquiry without practicing Buddhism.

Packer has also published a variety of articles and commentary on the Springwater website.