Sinner won the Australian Open and US Open for his first two grand slam titles. He mathematically secured the year-end No.1 a month ago.
"There's no place better to celebrate this trophy," Sinner said as his mother, Siglinde, looked on in tears.
"Thanks for all of your support."
The 23-year-old Sinner is the 19th different player to claim the year-end honour and the 29th man overall to be No.1.
"I think he's the man to beat for a long time," said former No.1 Boris Becker, who took part in Monday's trophy presentation in Turin.
The best of the best ��🇮🇹— ATP Tour (@atptour) Jannik Sinner receives the ATP Year-End No. 1 trophy presented by PIF on home soil! #PIF | #ATPRankings | #partner pic.twitter.com/boOV9m9jHaNovember 11, 2024
Sinner beat Australia's Alex de Minaur in his opening match on Sunday at the year-ending event for the top eight players and meets Taylor Fritz on Tuesday (Wednesday AEDT) in a rematch of the US Open final.
Sinner is playing at home for the first time since it was announced before his US Open title that he tested positive in two separate drug tests this year.
A decision to clear Sinner of wrongdoing was appealed by the World Anti-Doping Agency in September. A final ruling in the case is expected early next year.