He and his wife Brittany have a daughter, Aurora Robinson Perrineau

Perrineau is his mother's maiden name, and his father is Harold Williams Sr. His parents never married, so he used both names growing up, eventually settling on Williams. When he joined SAG there was already a Harold Williams, so he took the Perrineau from his mom and the Jr. from his dad for his stage name, even though there is no actual Harold Perrineau Sr.

He studied music & theater at the Shenandoah Conservatory.

Grew up in Brooklyn.

Harold's wife Brittany is a model/actress.