Girard is a city in southern Trumbull County, Ohio, United States, along the Mahoning River. The population was 9,603 at the 2020 census. Loca…Girard is a city in southern Trumbull County, Ohio, United States, along the Mahoning River. The population was 9,603 at the 2020 census. Located directly north of Youngstown, it is a suburb in the Youngstown–Warren metropolitan area.