Oatfield is an unincorporated community and census-designated place in Clackamas County, Oregon, United States. It is in the Portland metropolitan area. As of the 2010 census, the population of the CDP was 13,415.It is named after Oatfield Road, which runs between Milwaukie and Gladstone. Oatfield Road was named for the Oatfield family, well-known pioneers of the area.