NeathCastell-nedd
Former Seneddcounty constituencyfor the Senedd
Neath shown as one of the 40Senedd constituencies
Former Seneddcounty constituency
Created	1999
Abolished	2026
Party	Labour
MS	Jeremy Miles
Electoral region	South Wales West
Preserved county	West Glamorgan

Neath (Welsh: Castell-nedd) was a constituency of the Senedd. It elected one Member of the Senedd by the first past the post method of election. Also, however, it was one of seven constituencies in the South Wales Westelectoral region, which elected four additional members, in addition to seven constituency members, to produce a degree of proportional representation for the region as a whole.

From the creation of the assembly the constituency had returned a Labour AM, with varying majorities, from 7.7% to 26.8%. The last holder Jeremy Miles, was one of the first openly gay elected Members of the Senedd.^[1]Plaid Cymru were Labour's main opposition in the seat.

In the election in 2016 the constituency got the highest vote share from an Independent in Steve Hunt with 8.1% of the vote. Hunt was the only independent to save his deposit.

Map of 1999–2026 boundaries

The constituency was created for the first election to the Assembly, in 1999, with the name and boundaries of the Neath Westminster constituency. It was entirely within the preserved county of West Glamorgan.

The other six constituencies of the region were Aberavon, Bridgend, Gower, Ogmore, Swansea East and Swansea West.

In general elections for the Senedd, each voter had two votes. The first vote was used to vote for a candidate to become the Member of the Senedd for the voter's constituency, elected by the first past the post system. The second vote was used to vote for a regional closed party list of candidates. Additional member seats were allocated from the lists by the d'Hondt method, with constituency results being taken into account in the allocation.