An election to the 56th Parliament of the United Kingdom for the constituency area of Brentford and Isleworth, held as part of the general election on 7 May 2015.
Labour gain from Conservatives by Ruth Cadbury with a majority of 465 - 0.8% - on a turnout of 67.8%.
Candidates
| Name | Party | Vote | Vote share | Vote change |
| CADBURY, Ruth | Lab | 25,096 | 43.8% | 10.2% |
| MACLEOD, Mary | Con | 24,631 | 42.9% | 5.7% |
| HENDRON, Richard | UKIP | 3,203 | 5.6% | 4.0% |
| BOURKE, Joe | LD | 2,305 | 4.0% | -19.6% |
| GOLDSMITH, Daniel | Green | 2,120 | 3.7% | 2.2% |
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 84,602, having a valid vote count of 57,355 and an invalid vote count of 147.
Result declared at 04:57 on 8 May 2015.