Hefner died at age 91 from natural causes in his home on Wednesday, September 27, surrounded by loved ones, Peoplereported.
Hefner is survived by his third wife Crystal Harris and four children -- Christie, David, Marston and Cooper -- from his two previous decade-long marriages to Mildred Williams, whom he divorced in 1959, and Kimberley Conrad, whom he divorced in 2010.
"Hugh M. Hefner, the American icon who in 1953 introduced the world to Playboy magazine and built the company into one of the most recognizable American global brands in history, peacefully passed away today [at] The Playboy Mansion," Hefner's representative told People in a statement.
Hefner was born on April 9, 1926 in Chicago, IL, to parents Grace Caroline and Glenn Lucius Hefner.
After reportedly serving in the army and attending college, Hefner worked in the publishing industry and took out a loan to publish the very first issue of Playboy in December 1953, which featured a nude Marilyn Monroe. That same year, Hefner launched Playboy Enterprises, Inc.
"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," Hefner's son Cooper, the CCO of Playboy Enterprises, told the magazine.
"He defined a lifestyle and ethos that lie at the heart of the Playboy brand, one of the most recognizable 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."
The Girls Next Door -- which ran for six seasons on E! and wrapped in 2010 -- documented Hefner's life with the young women inside the mansion.
Hefner had a seven-year relationship with Madison that was featured on the show, but he ultimately married Harris on December 31, 2012.
Madison has yet to break her silence on Hefner's death, but Wilkinson and Marquardt both issued statements on the news.
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"Hef changed my life. He made me the person I am today," Wilkinson told People. "I couldn't be more thankful for our friendship and our time together. I will miss him so much but he will be in my heart forever."
Meanwhile, Marquardt shared a photo of Hefner and herself on Twitter and Instagram, captioning the photo, "So sad but forever grateful for all the wonderful memories and amazing experiences #RIPHef #Playboy."
The Playboy Mansion reportedly sold to Hefner's neighbor Daren Metropoulos for $200 million in June under the agreement he could live in the home until his passing.