Tributes have poured in for the MasterChef co-host from his family, the Australian TV industry and global celebrity chefs.
Zonfrillo passed away suddenly in Melbourne overnight, with Victoria Police confirming officers attended a hotel in Carlton to conduct a welfare check about 2am on Monday and found the body of a man.
His death is not being treated as suspicious and a report will be prepared for the coroner.
The TV presenter's family described him as an irreplaceable husband, father, brother, son and friend.
"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," they said in a statement.
"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's broadcaster Network Ten and production company Endemol Shine Australia said they were deeply shocked and saddened by the sudden loss.
"Jock's charisma, wicked sense of humour, generosity, passion and love for food and his family cannot be measured. He will be greatly missed," they said.
Born in Glasgow to an Italian father and Scottish mother, Zonfrillo moved to Australia permanently more than two decades ago.
He opened Adelaide restaurants Bistro Blackwood and Orana after working in top kitchens around the world including Marco Pierre White's acclaimed restaurant in London.
Zonfrillo won the prestigious Basque Culinary World Prize in 2018 and joined MasterChef Australia in 2019.
Chef Gordon Ramsay said he "truly enjoyed" the time the two spent together on the show.
"Sending all my love to Lauren and the family in this difficult time," he posted to social media.
Jamie Oliver worked with Zonfrillo on the upcoming series.
"Jock was very generous to me with his time and spirit in the show and for that I was very grateful," he wrote.
Singer Jimmy Barnes said he was speechless.
"Jock was like a brother to me and we made each other laugh and cry. My heart does out to his family," he said.
The star was loved by colleagues and would be deeply missed, Endemol Shine Australia chief executive Peter Newman said.
"Jock was an incredible talent, not just as a renowned chef but as someone who could bring joy into the homes of people in Australia and around the world in his role as judge on MasterChef Australia," he said.
The latest series of the program was due to premiere on Tuesday however the broadcaster said it would not air this week.
Zonfrillo is survived by wife Lauren Fried and children Ava, Sophie, Alfie and Isla.
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