Kinski was born in West Berlin as Nastassja Aglaia Nakszynski. She is the daughter of renowned German actor Klaus Kinski and his second wife, actress Ruth Brigitte Tocki. She is of partial Polish descent, for her grandfather Bruno Nakszynski was a Germanized ethnic Pole. Kinski has two half-siblings: Pola and Nikolai Kinski. Her parents divorced in 1968. After the age of 10, Kinski rarely saw her father. Her mother struggled financially to support them; they eventually lived in a commune in Munich.

In 1976, while still a teenager, Kinski had her first two major roles: in Wolfgang Petersen’s feature film-length episode Reifezeugnis of the German TV crime series Tatort. Next, she appeared in the British horror film To the Devil a Daughter (1976), produced by Hammer Film Productions, which was released in the UK just 40 days after Kinski’s fifteenth birthday, making it a virtual certainty she was only fourteen when her scenes were shot (including full frontal nudity). In regards to her early films, Kinski has stated that she felt exploited by the industry. In an interview with W, she said, “If I had had somebody to protect me or if I had felt more secure about myself, I would not have accepted certain things. Nudity things. And inside it was just tearing me apart.”

Kinski met the director Roman Polanski at a party in 1976. He urged her to study method acting with Lee Strasberg in the United States and she was offered the title role in Polanski’s upcoming film, Tess (1979). In 1978, Kinski underwent extensive preparation for the portrayal of an English peasant girl, which included acquiring a Dorset accent through elocution studies:

In 1976, when Kinski was aged 15, she reportedly began a romantic relationship with director Roman Polanski, who at the time was 43. Polanski confirmed the relationship in a 1994 interview with Diane Sawyer: “…what about Nastassja Kinski? She was young and we had a love affair.” However, in a 1999 interview in The Guardian, Kinski was quoted as saying that there was no affair and that, “There was a flirtation. There could have been a seduction, but there was not. He had respect for me.”

In 1978 Kinski starred in the Italian romance Stay as You Are (Così come sei) with Marcello Mastroianni, gaining her recognition in the United States after New Line Cinema released it there in December 1979. Time wrote that she was “simply ravishing, genuinely sexy and high-spirited without being painfully aggressive about it.” The film also received a major international release from Columbia Pictures.

In 1981 Richard Avedon photographed Kinski with a Burmese python coiled around her nude body. The image, which first appeared in the October 1981 issue of US Vogue, was released as a poster and became a best-seller, further confirming her status as a sex symbol.

In 1982 she starred in Francis Ford Coppola’s romantic musical One from the Heart, her first film made in the United States. Texas Monthly described her as acting “as a Felliniesque circus performer to represent the twinkling evanescence of Eros.” The film failed at the box office and was a major loss for Coppola’s new Zoetrope Studios. That year, she was also in the erotic horror movie Cat People. Dudley Moore’s comedy Unfaithfully Yours and an adaptation of John Irving’s The Hotel New Hampshire followed in 1984.

Kinski has three children from different relationships. Her first child, son Aljosha Nakszynski (born 29 June 1984), was fathered by actor Vincent Spano, her co-star in Maria’s Lovers. On 10 September 1984, Kinski married Egyptian filmmaker Ibrahim Moussa, with whom she had daughter Sonja Kinski (born 2 March 1986). The marriage was dissolved in July 1992. From 1992 until 1995, Kinski lived with musician Quincy Jones, though she kept her own apartment on Hilgard Avenue, near UCLA, at the time. They had a daughter, Kenya Julia Niambi Sarah Jones (born 9 February 1993), a model known professionally as Kenya Kinski-Jones.

In 1997, Kinski dated married producer Jonathan D. Krane during a brief separation from his wife, actress Sally Kellerman. Over the course of her career, Kinski has also been romantically linked with Paul Schrader, Jean-Jacques Beineix, Rob Lowe, Jon Voight, Gérard Depardieu, Dudley Moore, Miloš Forman and Wim Wenders. As of 2012, she was dating actor Rick Yune.

In a 1999 interview, Kinski denied that her father had molested her as a child, but said he had abused her “in other ways”. In 2013, when interviewed about the allegations of sexual abuse made by her half-sister Pola Kinski, she confirmed that he attempted with her, but did not succeed. She said, “He was no father. Ninety-nine percent of the time I was terrified of him. He was so unpredictable that the family lived in constant terror.” When asked what she would say to him now, if she had the chance, she replied, “I would do anything to put him behind bars for life. I am glad he is no longer alive.”

In 2001 Kinski stated in an interview in The Daily Telegraph that she was affected by the sleep disorder narcolepsy.

Her most recent films include David Lynch’s Inland Empire (2006) and Rotimi Rainwater’s Sugar (2013). In 2016, she competed in the German Let’s Dance show.

In the late 1970s, Kinski was roommates with a pre-fame Demi Moore. In her 2019 memoir Inside Out, Moore wrote: “We know each other in a way that no one else could.”