Rumney is a district and community in the east of the city of Cardiff, Wales. It lies east of the Rhymney River, and is historically part of Monmouthshire. On 1 April 1938 the Cardiff Extension Act 1937 incorporated it into the county borough of Cardiff, although it remained part of Monmouthshire, and England until the Local Government Act 1972 made Monmouthshire a part of Wales.