The 31-year-old has signed a three-year deal with the Foxes keeping him at the club until July 2018. Leicester City are yet to disclose the transfer fee paid to Napoli.
Leicester’s boss Claudio Ranieri has found his replacement for the former Real Madrid and Inter star Esteban Cambiasso. The Argentine left Leicester after turning down a new contract at the end of last season.
Inler scored one goal in 33 appearances for Napoli in all competitions last season. The 31-year-old has won 84 caps and played in two FIFA World Cups.
Leicester City have won their first two Premier League games of the season and find themselves in second place in the table.
Tottenham find themselves in 14th place after picking up just one point from their opening two games.