Published Friday, 27 January 2012
The 34-year-old, who has played club football with Manchester United and Wigan, amongst others, has signed an 18-month contract with the Greek champions.
"I'm very happy to have joined such a club," he told the Olympiakos website.
"It's a real honour to be part of Olympiakos, Greece's greatest team. I will do my best in order to contribute and help our squad accomplish its goals.
"I'm really looking forward to the Europa League games and my own comeback to European competition.
"I'm hoping that next year we will be playing in the Champions League, because everybody wants to play at the top level. In order to be able to do so, however, we must first win the championship."
Carroll has also played for West Ham and Hull City in England - in recent years he has played in Denmark for Odense and OFI Crete in Greece.