Calvin Richard Klein (born November 19, 1942) is a well-known American fashion designer. His name is also a brand name of clothing marketed by his company, which was launched in 1968.

In addition to clothing, Calvin Klein also gave his name to a range of perfumes, including CK One and CK Be (fragrances for both genders), now owned by Coty Inc. Swatch Group manufactures watches and jewelry under the Calvin Klein and Calvin Klein Jeans brands.

Born Richard Klein in The Bronx to Jewish Hungarian immigrants, he attended the High School of Industrial Art and he graduated, at 20 years of age, from New York's Fashion Institute of Technology. He did his apprenticeship in 1962 at an oldline cloak-and-suit manufacturer and spent five years designing at other New York shops. He later launched his first company with a childhood friend.

Klein was one of several design leaders raised in the Jewish immigrant community in the Bronx, New York along with Robert Denning and Ralph Lauren. Calvin Klein became a protégé of Baron de Gunzburg through whose introductions he became the toast of the New York elite fashion scene, even before he had his first mainstream success with the launch of his first jeans line. Later, speaking in an interview with Bianca Jagger and Andy Warhol for Interview magazine, published not long after the Baron's death, Klein said: "He was truly the greatest inspiration of my life... he was my mentor, I was his protégé. If you talk about a person with style and true elegance -- maybe I'm being a snob, but I'll tell you, there was no one like him. I used to think, boy, did he put me through hell sometimes, but boy, was I lucky. I was so lucky to have known him so well for so long." Calvin Klein was immediately recognised for his talent after his first major showing at New York Fashion Week. Klein was hailed as the new Yves Saint-Laurent, and was noted for his clean lines and straight cuts on coats and suits.