Charalampos is an 18-year-old midfielder from Greece who has played for the country's Under-21 team.
He has signed a five-year contract with Brighton, which will start on July 1st, pending international clearance.
Brighton's head coach, Fabian Hurzeler, is excited about the signing, saying that Charalampos is an "outstanding young player" who wants to play in the Premier League.
Charalampos has already shown his skills in the Greek league, scoring seven goals and providing two assists in 35 appearances for Olympiacos last season.
This is the third new signing for Brighton since the end of the season, following the arrivals of Tom Watson from Sunderland and Yoon Do-young from South Korea.
