Zonfrillo died in Melbourne on Sunday, MasterChef Australia confirmed on Monday afternoon.
"Network 10 and Endemol Shine Australia are deeply shocked and saddened at the sudden loss of Jock Zonfrillo, a beloved member of the MasterChef family," a statement from the program said.
"Jock was known to Australians as a chef, best-selling author, philanthropist and MasterChef judge but he will be best remembered as a loving father, husband, brother and son."
Born in Glasgow to an Italian father and a Scottish mother, Zonfrillo operated renowned restaurants in Sydney and Adelaide over two decades before becoming a judge on MasterChef in 2019 reports ABC.
Along with Melissa Leong and Andy Allen, he replaced the show's original hosts Matt Preston, George Calombaris and Gary Mehigan.
His family released a statement on Zonfrillo's personal Facebook page, paying tribute to him and calling for privacy: "With completely shattered hearts and without knowing how we can possibly move through life without him, we are devastated to share that Jock passed away yesterday.
"So many words can describe him, so many stories can be told, but at this time we're too overwhelmed to put them into words.
"For those who crossed his path, became his mate, or were lucky enough to be his family, keep this proud Scot in your hearts when you have your next whisky."
MasterChef Australia was due to return for its 15th season on Monday night, however Network 10 and Endemol Shine Australia have confirmed the show will not air this week.
Chef and MasterChef judge Jock Zonfrillo. Photo: Tina Smigielski