The France international has forged an impressive partnership with Per Mertesacker and reportedly attracted the attentions of Bayern Munich and Paris Saint-Germain
In a press conference on Thursday, Arsene Wenger revealed he was close to tying his star centre-back to an extension, and the France international has now put pen to paper on a new deal.
Koscielny has made 48 appearances for Arsenal this season, cultivating a formidable partnership with Per Mertesacker and reportedly attracting the attentions of Bayern Munich and Paris Saint-Germain.
"I am very proud to have reached agreement with the club on a new contract," he told the club's official website.
"I have enjoyed four great years at Arsenal already, and I look forward to continuing to help the team in the years to come."