1991 Dinefwr Borough Council election

An election to Dinefwr Borough Council was held in May 1991. It was preceded by the 1987 election and followed, after local government reorganization, by the first election to Carmarthenshire County Council in 1995. On the same day there were elections to the other local authorities and community councils in Wales.

Llandeilo Castle (one seat)
Boundary Change

Myddfai (one seat)
The ward was previously known as Llanddeusant and Myddfai

Pontamman (one seat)
Boundary Change