Gladstone is a city located in Clackamas County, Oregon, United States. As of the 2000 census, the city had a total population of 11,438. The 2007 estimate is 12,200 residents. 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.