Gladstone is a city located in Clackamas County, Oregon, United States. The population was 11,497 at the 2010 census. Gladstone is a four-square-mile (10 km²) suburban community twelve miles (19 km) south of Portland at the confluence of the Clackamas and Willamette rivers. To the south, across the Clackamas River, is Oregon City, across the Willamette is West Linn, to the north is Milwaukie.