Sir Bertram Clough Williams-Ellis (May 28, 1883 - April 9, 1978) was an architect, known chiefly as creator of the Italianate village of Portmeirion in North Wales.
Clough Williams-Ellis was born in Gayton, Northamptonshire, England, but his family moved back to his father's native Wales when he was four. He married the writer Amabel Strachey in 1915. In 1908, he inherited a small country house, Plas Brondanw in Merionethshire, from his father, restoring and embellishing it over the rest of his life, and rebuilding it after a fire in 1951. He served with distinction in World War I, and began work on Portmeirion during the 1920s. A fashionable architect in the inter-war years, his other works include buildings at Stowe in Buckinghamshire, and groups of cottages at Cornwell, Oxfordshire; Tattenhall, Cheshire, and Cushendun, County Antrim, Northern Ireland. Clough also served on several government committees concerned with design and conservation and was instrumental in setting up the British National Parks after 1945. He wrote and broadcast extensively on the preservation of the rural landscape. He was knighted in 1971 for "services to architecture and the environment". Clough's elder daughter, Susan Williams-Ellis, used the name Portmeirion Pottery for the company she created with her husband in 1961. Her son, Robin Llywelyn, is a much-admired Welsh language author.