Ryan Reynolds announced the tragic passing of his father on Wednesday. In a tweet, the Hollywood star shared a photo of his father with the message, "RIP Pops. James C. Reynolds. 1941-2015".
Ryan revealed in November 2014 that his father had battled Parkinson's for over two decades.
The Green Lantern star, who is married to Blake Lively, spoke with NBC Today about his father's struggle with Parkinson's.
"My father really hasn't ever said he has Parkinson's disease," Ryan said.
Ryan with his mother Tammy and father Jim at the Just Friends premiere in 2005
"He comes from a pretty prideful generation and he doesn't really talk about it too much. But he’s maybe said it once or twice out loud."
The actor said his father was diagnosed in 1995, which united Ryan's family as a result.
"It kind of galvanised everybody else, to sort of seek resources," he told Today. "And for us, it's in a strange way, it's really kind of brought us together."
Along with the touching photo he shared on Twitter, Ryan urged fans to donate to the Michael J. Fox Foundation, which he has been a member of since 2008. The star, who found out his father had the disease in 1995, has been an avid advocate for the foundation and is now on the board of directors.
Ryan and Michael J. Fox attended a benefit for the foundation in 2013
Back To The Future star Michael J. Fox, 54, was diagnosed with Parkinson's in 1991 but didn't go public with it until 1998.
Parkinson's is a degenerative neurological disorder that, according to the Michael J. Fox Foundation, affects more than five million people worldwide.
Symptoms include tremors, rigid muscles, impaired posture and balance, as well as changes in speech and the ability to write.
Ryan and wife Blake, who welcomed their daughter in December 2014, recently opened up about naming their beautiful baby girl James.
"It's a family name, and I liked having a boy's name," the former Gossip Girl actress admitted on Good Morning America.