Hugh Hefner, founder of the international adult magazine Playboy, has died at the age of 91.
Playboy Enterprises Inc said he passed away peacefully at home, from natural causes.
Hefner began publishing Playboy in his kitchen at home in 1953. It became the largest-selling men's magazine in the world, shifting seven million copies a month at its peak.
Cooper Hefner, his son, said he would be "greatly missed by many".
He paid tribute to his father's "exceptional and impactful life as a media and cultural pioneer," and called him an advocate for free speech, civil rights and sexual freedom.
Hefner's trailblazing magazine helped make nudity respectable in mainstream publications, despite emerging at a time when US states could legally ban contraceptives.
It also made him a multi-millionaire, spawning a business empire that included casinos and nightclubs.
The silk pyjama-clad mogul became famous for his hedonistic lifestyle, dating and marrying Playboy models. In his later years he threw decadent parties at his luxurious mansions in Chicago and Los Angeles.
He claimed to have slept with more than 1,000 women, and credited the impotence drug Viagra with maintaining his libido.
From 2005-10, a reality TV show called "The Girls Next Door" showcased Hefner's libertine lifestyle - and the harem of young blonde women who shared it.
In 2012, aged 86, he married his third wife Crystal Harris - who was 60 years his junior.
Though critics saw Playboy as a byword for sleaze, its founder never subscribed to that view.
He faced obscenity charges in 1963 for publishing and distributing Playboy, but was acquitted.
The magazine's most significant interviewees included civil rights leader Martin Luther King Jr, Beatle John Lennon, and Cuban revolutionary Fidel Castro.
"I've never thought of Playboy quite frankly as a sex magazine," Hefner told CNN in 2002. "I always thought of it as a lifestyle magazine in which sex was one important ingredient."