Playboy magazine founder Hugh Hefner has died at the age of 91, the company has confirmed on Twitter.
In a statement, Playboy Enterprises said Mr Hefner died peacefully at his home from natural causes.
It read: "Hugh M Hefner, the American icon who in 1953 introduced the world to Playboy magazine and built the company into one of the most recognisable American global brands in history, peacefully passed away today from natural causes at his home, The Playboy Mansion, surrounded by loved ones."
Hefner, known as the "Heff", built Playboy into a brand that defined the sexual culture of the second half of the 20th century.
The first issue of the magazine, published in 1953, featured nude photographs of Marilyn Monroe and sold more than 50,000 copies.
By the 1970s, the magazine had more than seven million readers, but competition and the advent of the internet saw that circulation drop to less than three million by the start of the 21st century.
As well as nude pictures, the magazine also included articles from writers including Kurt Vonnegut, Vladimir Nabokov and Alex Haley, as well as interviews with Fidel Castro, Martin Luther King Jr and John Lennon.
In 2015, Playboy stopped publishing images of naked women, citing the proliferation of nudity online.
In a New York Times interview in 1992, Hefner revealed he was most proud of changing "attitudes toward sex".
He said: "That nice people can live together now. That I decontaminated the notion of premarital sex. That gives me great satisfaction."
He was often seen wearing red silk pajamas, smoking a pipe, and accompanied by scantily clad models at fantasy parties he staged at his Playboy mansions first in Chicago and then in Los Angeles.
Hefner claimed to have had sex with more than a thousand women, including many of those pictured in his magazine.
He was married three times. In 1949, he wed Mildred Williams, and the couple had two children. They divorced in 1958.
In July 1989, he married Kimberley Conrad, then Playmate of the Year, who was 27. They also had two children together, but separated in 1998 although she continued living next door to the Playboy mansion.
Cooper Hefner, his son and chief creative officer of Playboy Enterprises, said in a statement: "My father lived an exceptional and impactful life as a media and cultural pioneer and a leading voice behind some of the most significant social and cultural movements of our time in advocating free speech, civil rights and sexual freedom.
"He defined a lifestyle and ethos that lie at the heart of the Playboy brand, one of the most recognisable and enduring in history.
"He will be greatly missed by many, including his wife Crystal, my sister Christie and my brothers David and Marston and all of us at Playboy Enterprises."
Six years ago he proposed to then 24-year-old Crystal Harris, a former Playmate. She called off the wedding days before the ceremony, but changed her mind and they eventually married in 2012.