Bronner was born in Heilbronn, Germany, to the Heilbronner family of soap makers. He emigrated to the United States in 1929, dropping “Heil” from his name because of its associations with Nazism. He became a naturalized citizen of the United States in 1936. As the family was Jewish, he pleaded with his parents to emigrate with him for fear of the then-ascendant Nazi Party, but they refused. His last contact with his parents was in the form of a censored postcard saying, “You were right. —Your loving father.” His parents were murdered in the Holocaust.

In 1946, while promoting his “Moral ABC” at the University of Chicago, Bronner was arrested for refusing to leave the dean’s office, despite the fact he was invited to the campus to lecture by a local student group, and then committed to the Elgin Mental Health Center, a mental hospital in Elgin, Illinois, from which he escaped after shock treatments. Bronner believed those shock treatments brought about his eventual blindness.

After moving his family several times, he settled in Escondido, California, where eventually his soap-making operation grew into a small factory. At his death in 1997, it produced more than a million bottles of soap and other products per year, but was still not mechanized. The firm has been the subject of many published articles and has supported many charitable causes.

His life was the subject of a 2007 documentary film, Dr. Bronner’s Magic Soapbox, which premiered on the Sundance TV channel, on 3 July 2007.