Sokratis Papastathopoulos, who was released by Arsenal last week, has returned to Greece after signing a two-and-a-half-year deal with Olympiakos, the Greek champions announced on Monday.
"The proposal was very good. It was easy to say yes," said the 32-year-old international defender.
"I did not come to Greece to end my career but to win."
Olympiakos are currently 11 points clear at the top of the Greek Super League after beating Atromitos at the weekend.
Papastathopoulos -- often referred to by his first name or 'Papa - joined Arsenal from Borussia Dortmund in July 2018 and made 69 appearances for the Gunners but was a fringe player under Michael Arteta.
He has also played for Werder Bremen, AC Milan, Genoa and AEK Athens.
Papastathopoulos has been a member of the Greek national team since 2008 making 90 appearances and scoring three goals.