France international Kante, 27, signed from Leicester in the summer of 2016, has been ever-present in Maurizio Sarri’s side this season.
“N’Golo Kante has today extended his stay at Stamford Bridge by signing a new five-year contract,” Chelsea said on their official website on Friday.
Kante added: “I’m happy to extend my time with Chelsea, it has been two beautiful years and I wish for more to come.
“Since I came, I completely improved as a player, challenged myself and got some awards I never thought about.”
Kante, whose new deal will keep him at Chelsea until 2023, signed a five-year contract when he joined the club in July 2016 from Leicester for a fee reported to be around £30million.
He arrived in England the previous summer when signed from Caen for £6m by Leicester, who he helped win the Premier League title in his first season. He was also named PFA and FWA player of the year.
Kante finished the 2016-17 campaign as a Premier League champion again with Chelsea and played a key role for France in Russia last summer when they won the World Cup.