Ruperra Castle or Rhiwperra Castle is a Grade II* Listed building and Scheduled Ancient Monument, situated in Lower Machen in the county borough of Caerphilly, Wales. Built in 1626, the castle is in a ruinous condition as at 2023. Its grounds are listed on the Cadw/ICOMOS Register of Parks and Gardens of Special Historic Interest in Wales.

Godfrey Charles Morgan, 1st Viscount Tredegar was a Welsh officer, a General in the British Army, and a peer in the House of Lords.