Christian Karl Gerhartsreiter (born February 21, 1961) is a German con artist who went by the alias Clark Rockefeller. He allegedly kidnapped his daughter, Reigh Storrow Mills Boss, on July 27, 2008, and was apprehended on August 2, 2008. Through fingerprint analysis, the FBI has confirmed that he is Christian Karl Gerhartsreiter of Bergen, Upper Bavaria in Germany. Alexander Gerhartsreiter, who lives in Bergen, identified Rockefeller as his brother, stating that they are the sons of a painter and homemaker.

Reportedly Gerhartsreiter came to the United States as a West German foreign exchange student in 1979. Although his family states that Christian Gerhartsreiter was born February 21, 1961, he maintains that he was born February 29, 1960. Rockefeller also told Boston police that his mother is Ann Carter, an American child actress of the 1940s, which Carter has denied.

On August 15, 2008 the FBI, the Massachusetts State Police, the Boston Police Department, and the Suffolk County District Attorney announced confirmation of the true identity of the individual who has used the aliases Clark Rockefeller, Chris C. Crowe, Chris Chichester, Charles Smith, and Chip Smith, among others. According to their report individual's true name is Christian Karl Gerhartsreiter. Gerhartsreiter was conclusively identified by means of forensic examinations conducted by the FBI Laboratory in Quantico, Virginia.