In a video he shared on Instagram, Stallone said a few words about his beloved co-star with a painting of them both from the film behind him.
"Today is an incredibly sad day for me," Stallone began. "I'm so torn up, I can't even tell you. I'm just trying to hold it in because Carl Weathers was such an integral part of my life, my success, everything about him -- I give him incredible credit and kudos because when he walked into that room, and I saw him for the first time, I felt greatness. But I didn't realize how great. I never could have accomplished what we did with 'Rocky' without him. He was absolutely brilliant, his voice, his size, his power, his athletic ability, but more importantly, his heart, his soul."
"It's a horrible loss," he said. "And I'm standing here in front of this painting, because it was probably the last moment we were ever in the ring together and I'll never forget it. He was magic. And I was so fortunate to be part of his life. So Apollo, keep punching."
Actor Arnold Schwarzenegger, who starred in "Predator" with Weathers in 1987, also paid tribute to him and called Weathers a "legend."
"Carl Weathers will always be a legend," Schwarzenegger said in an Instagram post. "An extraordinary athlete, a fantastic actor, and a great person. We couldn't have made Predator without him. And we certainly wouldn't have had such a wonderful time making it."
"Every minute with him - on set and off - was pure joy," he added. "He was the type of friend who pushes you to be your best just to keep up with him. I'll miss him, and my thoughts are with his family."
Weathers also famously starred in "Rocky" and most recently, in the series "The Mandalorian."
He died peacefully in his sleep on Thursday, Feb. 1, his family said in a statement obtained by ABC News. He was 76.
"Carl was an exceptional human being who lived an extraordinary life," his family said in the statement. "Through his contributions to film, television, the arts and sports, he has left an indelible mark and is recognized worldwide and across generations. He was a beloved brother, father, grandfather, partner, and friend."
Adam Sandler, who co-starred with Weathers in 1996's "Happy Gilmore," remembered the actor as "a true legend."
"A true great man. Great dad. Great actor. Great athlete," Sandler wrote on Instagram. "So much fun to be around always. Smart as hell. Loyal as hell. Funny as hell. Loved his sons more than anything. What a guy!! Everyone loved him. My wife and I had the best times with him every time we saw him. Love to his entire family and Carl will always be known as a true legend."
Michael B. Jordan
Michael B. Jordan, who plays the son of Weathers' "Rocky" character Apollo Creed in the "Creed" films, shared an Instagram story post about Weathers' death, writing, "We lost a Legend."
Pedro Pascal, who starred with Weathers in "The Mandalorian," reacted to Weathers' death on Instagram, writing, "words fail ."
"Good Morning America" co-anchor Michael Strahan reflected on playing Weathers' son on the sitcom "Brothers," calling it "an honor and privilege."
"RIP to the great Carl Weathers. It was an honor and privilege to play your son on the sitcom, Brothers!!" he wrote on Instagram. "You were an inspiration that made me feel like my dreams were attainable because you came from sports and conquered entertainment. You are loved and will be missed! My love and condolences to the Weathers family. RIP my friend ."
"Star Wars" actor Ahmed Best, who appeared in an episode of "The Mandalorian" directed by Weathers, shared a tribute to Instagram for the actor he called "a hero of mine since I was a child."
"I'm struggling with this one today. This is hard. Carl has always been a hero of mine since I was a child," he wrote. "I never thought I would ever be directed by him let alone have the honor to call him a friend. As an artist he was so generous with his wisdom and respect for the art of acting. He gave me golden nuggets that I will treasure and use for the rest of my life. As a director he was the one who gave me the space, grace, time, and guidance to come to life. He saw how nervous I was to be back in #starwars and gave me the strength and confidence to perform. Every conversation and text message after was bathed in love, mentorship and support. Love you my brother #carlweathers. I will miss you. We will miss you. Rest in Power. ."
Robert Rodriguez, who directed Weathers in an episode of "The Mandalorian," called the actor a "very kind and generous person."
"Will miss the great Carl Weathers who I was very fortunate to work with on several occasions," he wrote on Instagram. "A very kind and generous person. His performances were always electrifying and he was also a terrific director of both stage and screen."
Jesse Ventura, who starred alongside Weathers in "Predator," said with his death, Hollywood lost an "icon."
"We lost an icon. Carl Weathers was a phenomenal talent, a true professional, and a dear friend," he wrote on social media. "All my sympathies and love to his family. I loved working with him on Predator and then celebrating that film with him at various conventions in the ensuing years. Thank you, Carl."
Julie Bowen, who starred in "Happy Gilmore" with Weathers, paid tribute to Weathers on Instagram.
"Dearest Carl, you'll always be my Chubbs," Bowen said. "What a glorious spirit you had. Thanks for making me smile. I hope they golf wherever you are."
Magic Johnson remembered Weathers in a message he shared on X.
"Rest in peace to the truly amazing actor and entertainer, Carl Weathers," Johnson said. "We all marveled at his talents on the big screen in the 'Rocky' franchise as Apollo Creed, and I really enjoyed him in his role as the police chief in the hit TV show 'In the Heat of the Night'! Cookie and I are praying for the Weathers family during this difficult time. "
Danny Trejo, who worked together with Weathers on the TV series, "Explosion Jones," called Weathers a "beautiful soul."
"I had the pleasure of knowing and working with Carl Weathers, you were a beautiful soul," Trejo said on X. "May you rest in peace."
Actor Giancarlo Esposito remembered his "Mandalorian" co-star on social media and called Weathers a "dear friend and brother."
"You are truly one of the most wonderful human beings I have had the honor and pleasure of spending time with!" Esposito said. "I am grateful for your influence and support of all things good in my life. This is how I will always remember you. My dear friend and brother. "