The Paris-based designer will be the international guest of this year's iD Dunedin Fashion Week.
He will show his spring/summer collection to thousands at the Dunedin Railway Station, as part of the 15th anniversary iD Dunedin Fashion Show on April 4 and 5.
It will be the first showing of the collection in New Zealand.
Grant will also be a judge for the iD International Emerging Designer Awards.
He said he was delighted to be part of iD.
''Even after 25 years of living in Paris, I still have very strong ties with the Antipodes, and never having had the chance to visit New Zealand, I thought this was the perfect opportunity,'' he said.
''New Zealand has a strong fashion history and I am looking forward to discovering its new generation.''
The designer launched his first collection aged 16, and four years later was named Cointreau Young Designer of the Year.
He regularly dressed celebrities including Cate Blanchett, Tilda Swinton, Juliette Binoche, Cameron Diaz and Lady Gaga.
Last year he created new uniforms for Qantas.iD committee chairwoman Susie Staley said it would be the first time a current European collection had been shown as part of the Dunedin event.