Kirk Douglas turned 101 on Saturday (9 December) and his daughter-in-law, Catherine Zeta-Jones, took to social media to wish the Hollywood icon on his big day.

Kirk made his big screen debut in 1946 in the film The Strange Love of Martha Ivers. He received an honorary Oscar for his years of work in the film industry in 1996.

Taking to Instagram, the wife of Michael Douglas paid tribute to her father-in-law, saying he is her "hero". Michael and Zeta-Jones married in 2000 and share two children – Dylan and Carys Zeta.

She has shared a photo which shows Kirk and Zeta-Jones smiling at the camera with their arms around each other.

"101 today!!!! My darling Pappy on my knee," she wrote alongside the photo. "Happy Birthday to my wonderful, inspirational and loving father in law, Kirk. Love you with all my heart. ❤️#hero."

Wishes poured in for Kirk, with one fan taking to the comments section to say, "Happy, happy belated birthday ☃️GOD bless you!"

"Wow❣️ God bless you Kirk! He looks absolutely wonderful! And you Catherine, equally wonderful!" another fan said.

Someone else wrote, "Happy Birthday, Wow, 101 Good Going, Looking Fantastic.", while another admirer added, "Wow he cannot be 101! He looks amazing! Happy Birthday!"

Zeta-Jones had shared a sweet video last year, when When Kirk turned 100, that showed her father-in-law's life over the years.

Whenever there is a big occasion at home, Zeta-Jones usually shares posts on her social media feed.

When her son Dylan turned 17 on 8 August, she posted a clip on Instagram which showed Dylan's journey from a newborn child to a teenager.

"Don't 'START ME UP' on how much I love you," Catherine wrote next to the post that she shared with her fans on Instagram. She added, "Dylan, you are truly a remarkable young man. You are the joy of my life. 17 years old today! Happy Birthday sweetheart @dy1and."

Kirk Douglas
Catherine Zeta-Jones and her father-in-law Kirk Douglas (File photo) Reuters