Leah Miriam Lowenstein (née Hiller; June 17, 1930 – March 6, 1984) was an American nephrologist, academic administrator, and cellist. In 1982, she became the first woman dean of a co-educational, medical school in the United States upon her appointment at Jefferson Medical College. Lowenstein was previously associate dean and professor of medicine and biochemistry at the Boston University School of Medicine.