Capel Heol Dŵr was a Calvinistic Methodist chapel in the town of Carmarthen, Carmarthenshire, Wales.

[1] The key figure in the establishment of the cause at Water Street was Peter Williams, a native of the area who had been converted to Methodism in 1743 under the influence of George Whitfield.

[1] Capel Heol Dŵr was therefore an early Methodist chapel, and the present building dates from 1831.

The long-wall frontage has a pair of pedimented porches on Tuscan columns, each having a large arched window above.

In 2016 it was announced that the chapel would close due to rising costs and a decreasing membership.