McWilliam already has strong ties to New Zealand and to New Zealand wines.
The Scotsman proposed to his Aucklandborn wife, Gretchen Lister, at Waiheke Island vineyard Stoneyridge. The pair later married at Mudbrick Vineyard, also on Waiheke Island. McWilliam said he was honoured to take Cloudy Bay New Zealand to the Chelsea stage.
He was also keen to do future work in New Zealand and has his sights set on the Ellerslie Flower Show.
"We love the landscape, the people and the progressive architecture," McWilliam said.
"It would provide an excellent opportunity for me and Gretchen to spend more time with the family in Auckland if we landed some big schemes."
"We have also discussed taking part in the Ellerslie Flower Show at some point, either as designers or possibly on the judging front.
"My colleague Andrew has more than 17 years' judging experience for the Royal Horticultural Society."
• The Chelsea Flower Show runs from May 21 to 25.