Ceredigion (UK Parliament constituency) towns which comprised the Boroughs varied slightly over this long period, but primarily consisted of Cardigan, Aberystwyth, Lampeter and Adpar, the latter now a suburb of Newcastle Emlyn across the Teifi, in Carmarthenshire. The county constituency (for the purposes of type of returning officer and electoral expenses) was enlarged in 1983 with the addition of part of Pembrokeshire, being renamed Ceredigion and Pembroke North. In 1997 it reverted to its former boundaries, being renamed Ceredigion. The Ceredigion Welsh Assembly constituency was created with the same boundaries in 1999. Since 2017 the seat has been held in Parliament by Ben Lake
Ceredigion (Assembly constituency) of the county of Ceredigion. The constituency was created for the first election to the Assembly, in 1999, with the name and boundaries of the Ceredigion Westminster constituency. It is a Dyfed constituency, one of five constituencies covering, and entirely within, the preserved county of Dyfed. The other four Dyfed constituencies are Carmarthen East and Dinefwr, Carmarthen West and South Pembrokeshire, Llanelli and Preseli Pembrokeshire. They are all within the Mid and West Wales electoral region. The region consisted of the eight constituencies of Brecon and Radnorshire, Carmarthen East and Dinefwr, Carmarthen West and South Pembrokeshire, Ceredigion, Llanelli, Meirionnydd Nant