Genclerbirligi confirmed the signing of the 23-year-old from English Club Brighton &Hove Albion.
Manu was released by the newly-promoted English Premier League side after returning from a loan spell at Dutch side Go Ahead Eagles.
He joins fellow Ghanaian Kamal Issah at the Ankara-based Club and increases Ghana’s contingent in the Turkish top-flight to eight.
The Dutch-born Ghanaian will be hoping fight his way through to the Black Stars squad with his new deal.
Genclerbirligi who finished eighth the Turkish top-flight last season wants to beef up their squad for the new season.