The ex-Black Stars player joins the Phobians on a two year deal ahead of the start of the second round of the Ghana Premier League.
Muntari has been training with the Accra based club for sometime now after ending his stay with Spanish lower tier side Albecete.
The 35-year old left Ghana as a teenager in 2002 to join Udinese before moving on to enjoy huge success in his career in Europe, where he played for the likes of AC Milan and Inter Milan.
Sulley won several trophies in Europe including club football’s biggest trophy, the UEFA Champions League.
He was also a member of the Portsmouth team that won the FA Cup in 2008. He scored the important winner in the semi final against Manchester United.
His move to Hearts of Oak is seen a a major coup for the Phobians, who have reinforced their team with some big name signings including former defender Nuru Sulley.
Hearts of Oak finished the first round in 9th place with a game in hand.
The return of the Ghana Premier League is yet to be known after it was halted because of the outbreak of the coronavirus.
We can only wish him all the best!