Penarth is a town in the Vale of Glamorgan, Wales.
Penarth may also refer to:
- Penarth, Cardiganshire, a former hundred of Cardiganshire, Wales, UK
- Penarth, Delaware, an unincorporated community in New Castle County, Delaware, U.S.
- Penarth (Newtown and Llanllwchaiarn), a house in Powys, Wales
- Penarth Group, a Rhaetian age (Triassic) lithostratigraphic group
- Penarth RFC, a Welsh rugby union club