In a statement to ET on Friday, Fonda's family said he died after a battle with lung cancer. He was 79 years old.
“It is with deep sorrow that we share the news that Peter Fonda has passed away,” the statement reads. “[Peter] passed away peacefully on Friday morning, August 16 at 11:05 a.m. at his home in Los Angeles surrounded by family. 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," the statement continues. "As we grieve, we ask that you respect our privacy. 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."
Fonda was best known for his role in 1969's Easy Rider, which he also co-wrote. He won the Golden Globe Award for Best Actor for 1997's Ulee's Gold and also won the Golden Globe Award for Best Supporting Actor -- Series, Miniseries or Television Film for his role in 1999's The Passion of Ayn Rand.
He is the younger brother of actress Jane Fonda and the son of actor Henry Fonda. He is survived by his third wife, Margaret DeVogelere, and his children -- 55-year-old daughter Bridget and his 53-year-old son Justin.
In a statement to Variety about the sad news, Jane said, "I am very sad. He was my sweet-hearted baby brother. The talker of the family. I have had beautiful alone time with him these last days. He went out laughing."