The Hundred of Roose (sometimes called Rowse) was a hundred in Pembrokeshire, Wales. It has its origins in the pre-Norman cantref of Rhos and was formalised as a hundred by the Laws in Wales Acts 1535–1542. Its area was about 102 square miles (260 km2). The area became an English "plantation" in the 12th century, part of the English-speaking Little England beyond Wales.