Aberthaw Cement Works are cement works in the Vale of Glamorgan near the village of Aberthaw in Wales.
The Blue Lias limestone of Aberthaw was a source of hydraulic lime from early times, and it was made famous when it was selected by John Smeaton for the construction of the Eddystone Lighthouse.
The Aberthaw and Bristol Channel Portland Cement Company was established in 1912 by the Beynon family. The site at Aberthaw was chosen as it was near the necessary raw material, limestone and coal from the South Wales coalfield which was needed to heat the kilns. The works started in 1914 with two small wet process kilns with a production capacity of 120 tonnes per day each. A third wet kiln was added after the Second World War, and a fourth in 1957. This brought clinker capacity to 1200 tonnes per day.
In 1967, Kiln 5 (51°23′51″N 3°23′38″W / 51.39743°N 3.393965°W) was installed. This was a much more efficient dry process kiln. The wet process kilns were decommissioned in 1974, and Kiln 6 - also a dry kiln - (51°23′51″N 3°23′40″W / 51.397507°N 3.394326°W) was started in 1975. Kiln 6 remains in operation today.