Sharing a sweet throwback snap of the pair on Friday, the 76-year-old wrote: "Can't believe it's been a year since you left us. At 103, you picked a good time to check out. I love you with all my heart! #KirkDouglas." Underneath the post, Michael's wife Catherine Zeta-Jones commented: "Love you Pappy [kiss emoji]."
WATCH: Michael Douglas' sweet words about wife Catherine
It's been one year since the Hollywood couple mourned the loss of the Spartacus star, who passed away at age 103.
At the time, Michael released a lengthy statement, which read: "It is with tremendous sadness that my brothers and I announce that Kirk Douglas left us today at the age of 103. To the world he was a legend, an actor from the golden age of movies who lived well into his golden years, a humanitarian whose commitment to justice and the causes he believed in set a standard for all of us to aspire to."
"But to me and my brothers Joel and Peter he was simply Dad, to Catherine, a wonderful father-in-law, to his grandchildren and great grandchild their loving grandfather, and to his wife Anne, a wonderful husband," he added.
The Hollywood star died at the age of 103
"Kirk's life was well lived, and he leaves a legacy in film that will endure for generations to come, and a history as a renowned philanthropist who worked to aid the public and bring peace to the planet. Let me end with the words I told him on his last birthday and which will always remain true. Dad - I love you so much and I am so proud to be your son."
Kirk was a Hollywood heavyweight, working in cinema for over seven decades. He had 90 credits to his name - ranging from the 1940s to the 2000s.
He was perhaps best-known for Spartacus, a Stanley Kubrick film which won four Oscars. The late star was nominated for an Oscar three times; for Champion in 1949, The Bad and the Beautiful in 1852 and Lust for Life in 1956.
Although he never won the coveted award, Kirk was honoured in the 1996 Academy Awards for 50 years as a creative and moral force in the movie industry. He is survived by his wife of 65 years, Anne, and his three sons: Michael, Joel, and Peter. A fourth son, Eric, sadly died in 2004.
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