The jury delivered its decision in court late Thursday.
Owusu-Ansah, 30, had been charged with first-degree murder. His defence team had argued he should be charged with manslaughter in the case.
Owusu-Ansah was out on bail under house arrest in January 2013 when he killed Bridget Takyi, a 27-year-old mother of two on Etobicoke's Richgrove Drive.
Owusu-Ansah had been charged with assaulting Takyi with a weapon and threatening to kill her a month before the killing.
He is set to be sentenced at a later date.