"The Walt Disney Company mourns the loss of Cameron Boyce who was a friend to so many of us, and filled with so much talent, heart and life, and far too young to die," Iger wrote in a tweet.
"It is with a profoundly heavy heart that we report that this morning we lost Cameron," a spokesperson for the Boyce family told CBS News. "He passed away in his sleep due to a seizure which was a result of an ongoing medical condition for which he was being treated.
A Disney Channel statement said Boyce will be "dearly missed."
"From a young age, Cameron Boyce dreamed of sharing his extraordinary artistic talents with the world," a Disney Channel spokesperson said. "As a young man, he was fueled by a strong desire to make a difference in peoples' lives through his humanitarian work. He was an incredibly talented performer, a remarkably caring and thoughtful person and, above all else, he was a loving and dedicated son, brother, grandson and friend."
Boyce played Carlos, the son of 101 Dalmatians villain Cruella de Vil, on Disney's Descendants, which began as a 2015 TV movie and was followed by a short-form series and a movie sequel. He also starred on the Disney Channel's show Jessie and in feature films, including Grown-Ups and Grown-Ups 2. Grown-Ups star Adam Sandler remembered his young co-star in a touching online tribute.
"Too young. Too sweet. Too funny," Sandler wrote in part. "Thank you, Cameron, for all you gave to us. So much more was on the way. All our hearts are broken."
Descendants 3, Boyce's last film role before his death, will premiere on Disney Channel in August.