"I'm sure that Antonio Conte is one of the best coaches out there," Inter President Steven Zhang said.
"I'm certain that he'll help us achieve our objective and fulfil our mission, which has always remained the same: to make this club one of the best in the world again."
Conte was the head coach of Juventus, Internazionale's bitter rivals, when the Italian powerhouse won three consecutive Serie A titles from 2012-2014, including an unbeaten run in the 2011-2012 season, reports Xinhua news agency.
He was assigned as the Italy national team manager in 2014 and led the Azzurri to the quarterfinals of Euro 2016 before he decided to step down and return to club football.
The Italian took over Chelsea in 2016 and guided the Blues to the Premier League title with a record 30 league victories but parted ways with the club after Chelsea missed the UEFA Champions League qualification in the 2017-2018 season.
"A new chapter in my life is beginning, I'm really excited," Conte said in a club statement.
"I have chosen Inter because of the club it is, because of the project's sound basis and how ambitious it is. Because of Inter's history. I was struck by the club's transparency and the desire to bring Inter back to where it belongs."
The 18-time Serie A champions last won the league title in the 2009-2010 season and finished fourth in the 2018-2019 to book a season in the Champions League next season.
( With inputs from IANS )