Best known for his role in 1969's "Easy Rider," Fonda was part of a family of Hollywood heavyweights that included his dad, Henry Fonda, older sister Jane Fonda and daughter Bridget Fonda.
He shared writing and producing credits on "Easy Rider," which he starred in with Jack Nicholson and Dennis Hopper. The film's 50th anniversary was on July 14.
He was nominated for an Academy Award for the screenplay, which he wrote with Hopper and Terry Southern.
“[Peter] passed away peacefully on Friday morning, August 16 at 11:05am at his home in Los Angeles surrounded by family,” his family said in a statement provided to People. “The official cause of death was respiratory failure due to lung cancer.”
“In one of the saddest moments of our lives, we are not able to find the appropriate words to express the pain in our hearts. As we grieve, we ask that you respect our privacy,” the statement continued. “And, while we mourn the loss of this sweet and gracious man, we also wish for all to celebrate his indomitable spirit and love of life. In honor of Peter, please raise a glass to freedom.”