"Claudio is an important element to our squad," sporting director Alessio Secco said. "He is a player with great experience in spite of the fact that he is still 23-years-old."
The 23-year-old was clearly delighted at the latest show of faith from the Old Lady.
"I am very happy with the agreement," Marchisio enthused. "This signature will allow my career to continue at a prestigious club that I consider as a family.
"I have worn the Bianconeri shirt for 14 years and I hope to continue to win as I did in the youth sector.
"I want to thank the club, the technical staff and my teammates for the belief they have shown in me in recent months and the fans for the love they show towards me game after game."