The 25-year-old Spain international signed from Marseille in August 2012 and is now firmly established as a first-team regular for Jose Mourinho’s side.
He was named player’s player of the season at Chelsea last term and went to the recent World Cup in Brazil with the Spanish national side.
A statement on the Chelsea website on Tuesday read: “We are pleased to announce Cesar Azpilicueta has today signed a new five-year contract.
“The defender joined the Blues from Marseille in August 2012 and has so far made 95 appearances for the club, scoring once, in last season’s Capital One Cup victory at Arsenal.
“Azpilicueta, affectionately known as ‘Dave’ by supporters, ended his first Chelsea season by lifting the Europa League trophy in Amsterdam.
“Last season he was a member of the Premier League’s meanest defence, which conceded just 27 times in 38 games.”
Chelsea have made a fine start to the new season, winning all three of their Premier League games, and Azpilicueta has played every minute so far.
He made his senior international debut for Spain against Qatar in February last year and is now away with the squad once more, with the European qualifiers about to get under way.