The 54-year-old has not managed since he left Spurs by mutual consent in March 2023 after 16 months in charge.
Despite a disappointing time in North London, Conte has had a decorated coaching career after winning the Premier League in his first season at Chelsea (2016-17) and the FA Cup in his second before being sacked in 2018.
“Napoli is a place of global importance.
I am happy and excited at the idea of ​​sitting on the blue bench,” Conte said, who guided Inter Milan to their first Serie A title in 11 years back in 2021.
“I can certainly promise one thing, I will do my utmost for the growth of the team and the club.
My commitment, together with that of my staff, it will be total.”
The Italian also guided a dominant Juventus to three Serie A titles in a row between 2011-2014.
Napoli, who won Serie A for first time in 33 years last season, have struggled to replicate that achievement and finished tenth in the league this season.
Their poor form resulted in Slovakia boss Francesco Calzona joining the club in February on a short-term deal to the end of season, after sacking manager Walter Mazzarri after just three months in charge.