The passing of Armani has sparked an outpouring of grief, with tributes flowing in from Hollywood celebrities and ordinary people alike. Over a career spanning five decades, he built a business empire ranging from haute couture to home furnishing, with his name becoming synonymous with elegant simplicity.

"Everything he did in his life he did it out of passion," said Pier Carlo Bertoglio, who travelled from nearby Lodi to the Armani offices, where the designer's body is lying in state over the weekend before a private funeral on Monday.

"Everyone here today should testify to the love they have received from him."

John Elkann, the scion of Italy's prominent Agnelli family, and his wife Lavinia, were among the first visitors.

Elkann, who heads the Agnelli family's investment vehicle Exor, had previously discussed a potential combination with Armani to create an Italian luxury goods conglomerate, including Exor-owned sports car maker Ferrari. The talks led nowhere.

Armani, who had no children, has put in place measures to ensure continuity and independence for his business, which he ran with trusted family members and long-time colleagues.

Early visitors also included Milan Mayor Giuseppe Sala. Italy's fashion capital, where Armani relocated with his family after World War Two, will hold a day of public mourning on Monday.

"Milan is full of Armani 'signs', it would be impossible to forget him," Sala said. "His biggest legacy to the city I reckon is his profound belief in work as a means of self-realisation."

People queued silently under the trees that line the cul-de-sac where the Armani offices, designed by Japanese architect Tadao Ando, sit across from the Armani/Silos, a museum opened in 2015 to mark 40 years of his career and where the Armani Prive haute couture collections of the past 20 years are currently on display.

Visitors included fellow designer Donatella Versace, who arrived dressed in black carrying a bouquet of white orchids, Oscar-winning film director Gabriele Salvatores and actress Maria Grazia Cucinotta.

"Where I grew up in China, Armani's name is equal to Italian (style)," said Jonah Liu, who stood in the crowd sporting an Armani t-shirt and holding a small bunch of white daisies.

"He turned Italian elegance into a global fashion grammar ... I'm obliged to come here to pay my tribute to him."

In line with Armani's wishes, a separate entry was reserved for group staff.

"I'm one of his employees, so I'm sincerely attached to him," said Alessandra Caccavo, wiping away the tears.

"He made sure we never wanted for anything ... he was exceptional, so hospitable, ... we would always see him in the offices, which means a lot when you think who he was."