| Lagan Valley | Sorcha Eastwood | Alliance | 4 July 2024 |
| Lancaster and Wyre | Cat Smith | Labour | 7 May 2015 |
| Leeds Central and Headingley | Alex Sobel | Labour (Co-op) | 8 June 2017 |
| Leeds East | Richard Burgon | Labour | 7 May 2015 |
| Leeds North East | Fabian Hamilton | Labour | 1 May 1997 |
| Leeds North West | Katie White | Labour | 4 July 2024 |
| Leeds South | Hilary Benn | Labour | 10 June 1999 |
| Leeds South West and Morley | Mark Sewards | Labour | 4 July 2024 |
| Leeds West and Pudsey | Rachel Reeves | Labour | 6 May 2010 |
| Leicester East | Shivani Raja | Conservative | 4 July 2024 |
| Leicester South | Shockat Adam | Independent | 4 July 2024 |
| Leicester West | Liz Kendall | Labour | 6 May 2010 |
| Leigh and Atherton | Jo Platt | Labour (Co-op) | 4 July 2024 |
| Lewes | James MacCleary | Liberal Democrat | 4 July 2024 |
| Lewisham East | Janet Daby | Labour | 14 June 2018 |
| Lewisham North | Vicky Foxcroft | Labour | 7 May 2015 |
| Lewisham West and East Dulwich | Ellie Reeves | Labour | 8 June 2017 |
| Leyton and Wanstead | Mr Calvin Bailey | Labour | 4 July 2024 |
| Lichfield | Dave Robertson | Labour | 4 July 2024 |
| Lincoln | Mr Hamish Falconer | Labour | 4 July 2024 |
| Liverpool Garston | Maria Eagle | Labour | 1 May 1997 |
| Liverpool Riverside | Kim Johnson | Labour | 12 December 2019 |
| Liverpool Walton | Dan Carden | Labour | 8 June 2017 |
| Liverpool Wavertree | Paula Barker | Labour | 12 December 2019 |
| Liverpool West Derby | Ian Byrne | Labour | 12 December 2019 |
| Livingston | Gregor Poynton | Labour | 4 July 2024 |
| Llanelli | Dame Nia Griffith | Labour | 5 May 2005 |
| Lothian East | Mr Douglas Alexander | Labour (Co-op) | 4 July 2024 |
| Loughborough | Dr Jeevun Sandher | Labour | 4 July 2024 |
| Louth and Horncastle | Victoria Atkins | Conservative | 7 May 2015 |
| Lowestoft | Jess Asato | Labour | 4 July 2024 |
| Luton North | Sarah Owen | Labour | 12 December 2019 |
| Luton South and South Bedfordshire | Rachel Hopkins | Labour | 12 December 2019 |