The WWE Hall of Fame member was 79.
"A true trailblazer of the industry, Patterson was linked to many 'firsts' in sports-entertainment throughout his storied career," World Wrestling Entertainment said in a statement. "In a career spanning six decades, the renaissance man left an indelible mark on the industry in the ring, on the microphone and behind the scenes."
Pro wrestler John Cena said he'll never forget Patterson's friendly demeanor and zest for life.
"Pat Patterson lived life as it should be lived with passion, love and purpose," Cena said in a statement. "He helped so many and always entertained with a story or joke. He will live on in my life always. Love you Patrick."
Hossein Khosrow Ali Vaziri, better known as The Iron Sheik, tweeted an all-caps eulogy of his contemporary, lauding Patterson's "beautiful mind for this business and beautiful heart for this world."
"I don't know what to say other than I love you," he wrote. "My heart is broken. God bless you and your family. Thank you for your friendship."
Longtime WWE referee Charles Robinson said he'll miss seeing his old friend in the ring, backstage, on press row and even at the karaoke bar.
"One of the greatest minds in the business and just an all around great guy," Robinson said. "I will miss him and his karaoke! RIP my friend. You are a hero to many!"
The teenaged Patterson was thrown out of his home in Montreal after coming out to his parents and did the unthinkable — immigrated to America to make it in the hyper-macho world of pro wrestling, he wrote in his biography, "Accepted: How the First Gay Superstar Changed WWE."
He was the first to hold the title of Intercontinental Champion in 1979, and his early-'80s rivalry with Sgt. Slaughter took pro wrestling to new heights of popularity.
It culminated in the famed "Alley Fight at Madison Square Garden" in New York City on May 4, 1981.
This story first appeared on NBCNews.com.