An election to the 58th Parliament of the United Kingdom for the constituency area of Hertsmere, held as part of the general election on 12 December 2019.
Conservative hold by Oliver Dowden with a majority of 21,313 - 40.8% - on a turnout of 70.6%.
Candidates
| Name | Party | Vote | Vote share | Vote change |
| DOWDEN, Oliver | Con | 32,651 | 62.5% | 1.4% |
| KAL-WEISS, Holly | Lab | 11,338 | 21.7% | -6.9% |
| BARRETT, Stephen | LD | 6,561 | 12.6% | 7.2% |
| HUMPHRIES, John | Green | 1,653 | 3.2% | 1.3% |
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 73,971, having a valid vote count of 52,203 and an invalid vote count of 268.
Result declared at 02:35 on 13 December 2019.