Jean Struven was born on April 27, 1923, in Chicago, Illinois. She was the second of four children in her family, with parents named Albert and Mildred Struven. Growing up, she attended Laurel School in Shaker Heights, Ohio. After completing her education there, she moved on to Smith College in Northampton, Massachusetts.

At Smith College, Jean excelled academically. She graduated magna cum laude in 1945 with a degree in economics. Following her college graduation, she got married to Jim Harris. The couple had two sons by 1952. However, their marriage ended in divorce in 1965. Jim Harris passed away in 1977.

In December 1966, Jean met Dr. Herman Tarnower, a cardiologist who would later become famous for his diet book. They started a relationship that lasted for 14 years. During this time, Jean worked as the headmistress of the Madeira School for girls in McLean, Virginia. While she was busy with her career, her relationship with Tarnower included gifts and vacations, but he also had relationships with other women.

Jean Harris was aware of Tarnower's affairs, as he did not try to hide them from her. Over the years, Tarnower prescribed Jean various medications, including methamphetamines. In the 1970s, he hired a young divorcée named Lynne Tryforos as his secretary, and he began another affair with her.

In late winter 1980, Jean Harris drove from the Madeira School in Virginia to Herman Tarnower's home in New York. She carried a .32 caliber revolver with her. Harris claimed she intended to say goodbye before committing suicide. When she arrived, she found lingerie belonging to Tarnower's secretary, Lynne Tryforos, which led to an argument. During the argument, Tarnower reportedly told her to leave and that she was "crazy."

Harris stated that a struggle over the gun ensued when she threatened to kill herself. She shot Tarnower four times at close range. After the shooting, Harris tried to call for help, but the phone did not work. She left to seek help, unaware that the housekeeper had already called the police. When Harris saw police cars driving toward Tarnower’s home, she turned around and followed them back.

Harris was arrested and charged with second-degree murder. She pleaded not guilty, claiming the shooting was an accident during the struggle. After her arrest, she was released on bail and entered a psychiatric evaluation program.

The trial began on November 21, 1980, and lasted for 14 weeks. Harris took the stand but was convicted by the jury after deliberating for eight days. She was denied inheritance from Tarnower’s will due to her conviction. The judge sentenced her to a minimum of 15 years to life in prison.

While in prison, Harris worked to improve education for fellow inmates, setting up programs for GED and college classes. She also created a parenting class and an in-prison nursery. In 1992, her sentence was commuted by Governor Mario Cuomo, and she was released from prison. Later, she moved to a retirement home in Connecticut.

Jean Harris died of natural causes on December 23, 2012, at the age of 89. She had two sons, David and Jimmie, who survived her.