He will be tasked with reviving the fortunes of a label that accounted for two-thirds of Kering's profits in 2021, but has since been losing momentum.
The 39-year-old began his career at Prada, before moving to Dolce & Gabbana and then Valentino.
There he was appointed the brand's fashion director, overseeing both men's and women's collections.
In Kering's statement, De Sarno said he was proud to join a house with 'extraordinary history and heritage'.
Gucci had been under pressure to appoint someone to one of the top jobs in fashion after the abrupt departure in November of former creative chief Alessandro Michele.
It has been lagging rivals including Hermes and LVMH's top brand Louis Vuitton, with its performance in the key Chinese market becoming a concern for investors.
That's one factor that has made Kering the worst performer among major luxury stocks, and investors apparently remain to be convinced.
Shares in the firm were down around half a percent early Monday (January 30) following the weekend news of De Sarno's appointment.
