Results for the UK general election on 12 December 2019 Wales - Elections contested by Social Democratic Party
| Constituency | Candidate | Electorate | Turnout | Votes | Vote share | Vote change | Position |
| Cynon Valley | MCLEAN, Ian | 51,134 | 59.1% | 114 | 0.4% | - | 7th |
| Neath | WILLIAMS, Carl | 56,419 | 65.1% | 67 | 0.2% | - | 8th |
Turnout as calculated by the House of Commons Library, is the total number of votes cast and not spoiled, divided by the size of the electorate.
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.