Grand Island is on the land lying between Sycamore Slough and the Sacramento River. A post office operated at Grand Island from 1854 to 1919.
Grand Island is located in Sacramento County, California at 38°14′08″N 121°34′45″W / 38.23556°N 121.57917°WCoordinates: 38°14′08″N 121°34′45″W / 38.23556°N 121.57917°W