An election to the 57th Parliament of the United Kingdom for the constituency area of Carmarthen East and Dinefwr, held as part of the general election on 8 June 2017.
Plaid Cymru hold by Jonathan Edwards with a majority of 3,908 - 9.5% - on a turnout of 73.3%.
Candidates
| Name | Party | Vote | Vote share | Vote change |
| EDWARDS, Jonathan | PC | 16,127 | 39.3% | 0.9% |
| DARKIN, David | Lab | 12,219 | 29.8% | 5.6% |
| HUGHES, Havard | Con | 10,778 | 26.3% | 5.1% |
| HAMILTON, Neil | UKIP | 985 | 2.4% | -8.7% |
| PROSSER, Lesley | LD | 920 | 2.2% | -0.1% |
Under section 13(b) of the Representation of the People Act 1985, a candidate gaining 5% or less of the vote share will forfeit their deposit.
An electorate of 55,976, having a valid vote count of 41,029 and an invalid vote count of 45.
Result declared at 01:57 on 9 June 2017.