Whitland was founded on 16 September 1140 by monks from the mother house of Clairvaux. In 1144 it was located at Little Trefgarn near Haverfordwest. It moved to Whitland in about 1155, a site having been granted by John of Torrington. The abbey founded a number of daughter houses in Wales, starting with an abortive foundation at Abbeycwmhir in 1143. In 1164 a group of monks from Whitland founded Strata Florida Abbey. Strata Marcella Abbey was founded from Whitland in 1170, and in 1176 Cwmhir Abbey was re-founded.
Whitland Abbey was originally a Cambro-Norman foundation, but soon came under the control and patronage of Rhys ap Gruffudd, Prince of Deheubarth. It was at Whitland that Rhys's son, Maredudd, ended his days as a monk after he had been blinded by order of King Henry II of England when a hostage in England. It became an important cultural centre for south-west Wales and a strong supporter of the Welsh struggle to remain free of English domination.
Very little now remains at the site, only the grass-covered foundations of the walls.