Gudrun Ensslin was born in the German village of Bartoloma on August 15, 1940, as the fourth of seven children. Her father, Helmut Ensslin, was a pastor of the Evangelical Church in Germany, also known as EKD.

Gudrun was a stereotypical good girl, who did well at school and enjoyed reading the Bible. In her family, the social injustices of the world were often discussed and Gudrun is said to have been sensitized to social problems in West-Germany and the world as a whole.

At the age of eighteen, Gudrun got the chance to spend a year in the United States of America, where she attended a high school in Pennsylvania. She was offended by much she saw in the US, however.

After high school, Gudrun went to study philosophy, Anglistics and Germanistics, where she met Bernward Vesper, a left-wing German. Together with two other students, Ensslin and Vesper started a small business, a publishing house called Studio neue Literatur. At this time, Ensslin also tried to become a teacher, but her skills were only 'adequate', which demotivated her.

In 1965 Gudrun and Bernward married and went to West-Berlin, where Gudrun worked on a doctorate at the Free University. In West-Berlin, they demonstrated against the Bomb and the presence of American military bases.

In 1967, Ensslin gave birth to a son, Felix Robert. the marriage between Ensslin and Vesper was doing bad however, as Ensslin acted in a cheap porno movie and become more and more engrossed by leftist literature.

On June 2, Ensslin went into a demonstration against the visiting of the Shah of Iran, who, though viewed by the West as a reformer, was known to be brutal against political opponents and head of a police force (SAVAK) that tortured its prisoners. During this infamous demonstration, fights broke out between pro-Shah and anti-Shah spectators of the arrival of the Shah. A young man by the ironical name of Benno Ohnesorg was shot in the back of the head by a police officer. This killing was the start of a terrorist organisation known as the Movement 2 June, which would become allied to the Baader-Meinhof Gang.

The next night, Gudrun Ensslin angrily denounced the fascist state at a leftist meeting.

The killer officer, Karl-Heinz Kurras, was charged with manslaughter instead of murder and when he was acquitted of this charge on November 23, 1967, there was public outrage. In a year, things cooled down however, and this enraged Ensslin so much that she gave her child to her father to take part in the revolution. At this time she met Andreas Baader, with whom she became romantically acquainted. Under the influence of Ensslin, Baader became more of a leftist, and left his old habits. Together they founded the Rote Armee Fraktion, the most famous German terrorist group of the postbellum.

She hanged herself early in the morning of October 18, 1977.