Crystal Klein (born October 10, 1981 in Vienna, Austria) is an American-based pornographic actress and model. Klein is one of the few women to have been both a Playboy Playmate (Croatian Playboy, October 2004, as Christiane Vogt) and a Penthouse Pet of the Month (March 2005).

Klein studied psychology at the University of Vienna for two years but burned out. In January 2003, she moved to Maui as a break from university. To earn cash, she began working as a swimsuit model. Klein had an early unpleasant encounter with one photographer who shoots for the amateur contests for Hustler.

Soon after she was noticed by an agent from Matrix Models and flew to Los Angeles where she began working with the top photographers in the adult business - people such as Suze Randall, Earl Miller and J. Stephen Hicks.

She has appeared in the video Sheer Hosed Showoffs, played the piano while nude on The Howard Stern Show and has her own website.