Helen Prejean CSJ (/preɪˈʒɑːn/ pray-ZHAHN;[1] born April 21, 1939) is a Catholic religious sister and a leading American advocate for the abolition of the death penalty.

She is known for her best-selling book, Dead Man Walking (1993), based on her experiences with two convicts on death row for whom she served as spiritual adviser before their executions.

She helped establish The Moratorium Campaign, seeking an end to executions and conducting education on the death penalty.

In 1982 an acquaintance asked her to correspond with convicted murderer Elmo Patrick Sonnier, held on death row in the Louisiana State Penitentiary, known as Angola.

The experience gave Prejean greater insight into the process involved in executions, for the convict, families, and others in the prison, and she began speaking out against capital punishment.

The organization Witness to Innocence,[12] composed of death row survivors who were exonerated after being convicted for crimes they did not commit, was started under The Moratorium Campaign.

The book also examines the recent history of death penalty decisions by the Supreme Court of the United States and the record of George W. Bush as Governor of Texas.

In 1998, Prejean was given the Pacem in Terris Award, named after a 1963 encyclical letter by Pope John XXIII that calls on all people of good will to secure peace among all nations.

She and her sister Mary Ann Antrobus have also been deeply involved at a center in Nicaragua called Friends of Batahola.