Llanarth Court is a late-18th-century country house with substantial 19th-century alterations in Llanarth, Monmouthshire, Wales. The court was built for the Jones family of Treowen and was subsequently the home of Ivor Herbert, 1st Baron Treowen, whose family still owns much of the Llanarth estate, although not the court itself. The court is a Grade II* listed building and is now a private hospital. The gardens are included on the Cadw/ICOMOS Register of Parks and Gardens of Special Historic Interest in Wales.

Major-General Ivor John Caradoc Herbert, 1st Baron Treowen, CB, CMG, KStJ, known as Sir Ivor Herbert, Bt, between 1907 and 1917, was a British Liberal politician and British Army officer in the Grenadier Guards, who served as Officer Commanding the Militia of Canada from 1890 to 1895. He was made a baronet in 1907 and raised to a barony in 1917.