The third election to the Carmarthenshire County Council in Wales was held in May 2004. It was preceded by the 1999 election and followed by the 2008 election. As in previous elections, the Independent councillors had the largest number of seats. This resulted in a coalition between Independent and Labour Councillors for the next four years.
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The sitting Plaid Cymru councillor, John Crossley, chose to contest Llangeler and the party did not field a candidate, leading to the loss of the seat to the Independents.
Tegwen Devichand was elected at a by-election following the death of the previous councillor, Vernon Warlow.
William James crossed the floor from Independents in the previous term.
Although the sitting councillor, a former Labour member of Llanelli Borough Council, was elected as an Independent Labour candidate in 1995, he subsequently joined the Independent group.
The elected candidate, who had sat as a Ratepayer for Gorslas since 1995, and on Dyfed County Council since 1977, had now joined the Independent group.
Anthony Wyn Jones was elected at a by-election following the death of the previous Independent councillor, Gerald Earl.
No Boundary Change. Ward named changed.
The elected candidate was the sitting councillor for Cenarth since 1999.
Osi Rhys Osmond had been elected at a by-election following the death of the previous Independent councillor, Arthur Harries.
Dillwyn Bowen was the Labour councillor for Bynea from 1995 until de-selected by the Labour Party prior to the 2004 election. He then chose to contest Llwynhendy alongside sitting Independent councillor Don Davies, who had himself been de-selected by Labour prior to the 1999 election.
Joy Williams captured the seat for Plaid Cymru at a by-election following the death of the previous Independent Labour councillor, Ieuan Edwards.