PHOTO: Nemanja Matic holding the Chelsea shirt
The 25-year-old has been given a five-and-a-half year contract and will wear the no 21 jersey for the Blues.
Matic was signed in 2009 but after failing to make any significant impact, he was sold to Benfica in a cash plus part exchange deal that saw defender David Luiz coming to Stamford Bridge.
The Serbian international, who delivered a heart-felt farewell message yesterday to Benfica fans, said upon signing:
“I am very happy for this opportunity to be back at this club. I feel very good because of that and just want to say I will give my best to help the team and make the Chelsea fans happy.”