Will Smith's ex-wife Sheree Fletcher confirmed the sad news on Instagram on Monday.
"We're gonna miss you Daddio," she penned, alongside a photograph of Willard Sr, Will, and Will and Sheree's son, Trey Smith.
"You lived & played by your own rules… you truly were 1 of a kind. You instilled discipline, and a work ethic that has created a legacy in your honour! #RIPDaddio #donttellmetheresnothingyoucantdo #WillSMITH1."
Will was married to Trey's mum between 1992 till 1995, and the couple share their only son together, Trey, now 23.
The Fresh Prince of Bel-Air went on to become one half of Hollywood power couple with Jada Pinkett, with the duo tying the knot in 1997.
Together they are the proud parents to their two kids, 18-year-old son Jaden and 16-year-old daughter Willow.
The 48-year-old, who is named after his father, is yet to comment on the news.
In the past, the acting superstar has spoken about Willard being a "steady and positive figure" in his life.
"Dad was tough but not tyrannical. He kept me in line. He'd get this look that said, 'One more step. Will, and it will get ugly," Will mused to Essence magazine.
"He was an independent businessman – he set up refrigeration in supermarkets – and he always provided for us."
Our thoughts go out to the family.