Carmarthen East and Dinefwr is a constituency of the National Assembly for Wales. It elects one Assembly Member by the first past the post method of election. Also, however, it is one of eight constituencies in the Mid and West Wales electoral region, which elects four additional members, in addition to eight constituency members, to produce a degree of proportional representation for the region as a whole. It had been held since its formation in 1999 by the Plaid Cymru politician, Rhodri Glyn Thomas until his retirnment in 2016, it is now held by Plaid Cymru politician Adam Price.