Klaus Kinski (German: [klaʊs ˈkɪnski] ^ⓘ; born Klaus Günter Karl Nakszynski 18 October 1926 – 23 November 1991) was a German actor. Equally renowned for his intense performance style and notorious for his volatile personality, he appeared in over 130 film roles in a career that spanned 40 years, from 1948 to 1988. He is best known for starring in five films directed by Werner Herzog from 1972 to 1987 (Aguirre, the Wrath of God; Nosferatu the Vampyre; Woyzeck; Fitzcarraldo; and Cobra Verde), who would later chronicle their tumultuous relationship in the documentary My Best Fiend.

Kinski's roles spanned multiple genres, languages, and nationalities, including Spaghetti Westerns, horror films, war films, dramas, and Edgar Wallace krimi films. His infamy was elevated by a number of eccentric creative endeavors, including a one-man show based on the life of Jesus Christ, a biopic of violinist Niccolò Paganini directed by and starring himself, and over twenty spoken word albums.

Kinski was prone to emotional and often violent outbursts aimed at his directors and fellow cast members, issues complicated by a history of mental illness. Herzog described him as "one of the greatest actors of the century, but also a monster and a great pestilence."

Posthumously, he was accused of physically and sexually abusing his daughter Pola. His notoriety and prolific output have developed into a widespread cult following and a reputation as a popular icon.

Klaus Günter Karl Nakszynski was born on 18 October 1926 in Zoppot, Free City of Danzig (now Sopot, Poland). His father, Bruno Nakszynski, worked as an opera singer before becoming a pharmacist, while his mother, Susanne Lutze, was a nurse and the daughter of a local pastor. He had three older siblings; Inge, Arne, and Hans-Joachim. Due to the Great Depression, his family was unable to make a living in Danzig and moved to Berlin in 1931, where they also experienced financial difficulties. The family settled in an apartment in the Schöneberg district of the city and acquired German citizenship. In 1936, he began attending the Prinz-Heinrichs-Gymnasium [de] in Schöneberg.

Kinski was conscripted into the Wehrmacht in 1943 at the age of 17, serving in a Fallschirmjäger unit. He saw no action until the winter of 1944, when his unit was transferred to the German-occupied Netherlands and he was captured by the British Army on his second day of combat. In his 1988 autobiography, he claimed that he had decided to desert from the Wehrmacht and had been recaptured by German forces and sentenced to death in a court-martial before escaping and hiding in the woods, subsequently encountering a British patrol which shot him in the arm and captured him. After being treated for his wounds and interrogated, he was transferred to a prisoner-of-war camp in Colchester, Essex; the ship transporting him to Britain was torpedoed by a German U-boat but arrived safely.

In his documentary My Best Fiend, Werner Herzog claimed that Kinski had fabricated much of his 1988 autobiography, including claims of maternal sexual abuse, incest, and childhood poverty; according to Herzog, Kinski was actually raised in a financially stable upper middle class family.

While interned at Berechurch Hall in Colchester, Kinski played his first roles on stage, taking part in variety shows intended to maintain morale among the prisoners. By May 1945, at the end of the war in Europe, the German POWs were anxious to return home. Kinski had heard that sick prisoners were to be returned first, and tried to qualify by standing outside naked at night, drinking urine and eating cigarettes. He remained healthy, however, and was returned to Germany in 1946.