Attendees include prominent designers Tom Ford and Donatella Versace, Vogue's Anna Wintour, and Hollywood star Anne Hathaway.
Garavani, who passed away on Monday aged 93, was celebrated for dressing generations of royalty, first ladies, and celebrities like Jackie Kennedy Onassis and Julia Roberts.
Tributes have poured in from across industries, including Italian Prime Minister Giorgia Meloni, who described him as an "undisputed master of style and elegance".