| Party | Name | Ward | End of Term | Byelection |
|---|
| CON | Jonathan Boulton | Brookmans Park and Little Heath | 02-05-2019 | - |
| CON | Stephen Boulton | Brookmans Park and Little Heath | 07-05-2020 | - |
| CON | Rebecca Louise Lass | Brookmans Park and Little Heath | 05-05-2022 | - |
| CON | Barbara Fitzsimon | Haldens | 02-05-2019 | - |
| LAB | Mike Larkins | Haldens | 07-05-2020 | - |
| LAB | Lucy Musk | Haldens | 05-05-2022 | - |
| CON | Helen Bromley | Handside | 02-05-2019 | - |
| CON | Fiona Thomson | Handside | 07-05-2020 | - |
| LD | Siobhan Elam | Handside | 05-05-2022 | - |
| LAB | Maureen Cook | Hatfield Central | 07-05-2020 | - |
| LAB | Glyn Hayes | Hatfield Central | 02-05-2019 | - |
| LAB | Pankit Shah | Hatfield Central | 05-05-2022 | - |
| CON | Caroline Gillett | Hatfield East | 02-05-2019 | - |
| CON | Kerstin Holman | Hatfield East | 07-05-2020 | - |
| CON | Peter Hebden | Hatfield East | 05-05-2022 | - |
| LAB | James Broach | Hatfield South West | 02-05-2019 | - |
| LAB | John Fitzpatrick | Hatfield South West | 07-05-2020 | - |
| LAB | Kieran Thorpe | Hatfield South West | 05-05-2022 | - |
| CON | Duncan Bell | Hatfield Villages | 05-05-2022 | - |
| LAB | Tara-Mary Lyons | Hatfield Villages | 02-05-2019 | - |
| CON | Samuel Kasumu | Hatfield Villages | 07-05-2020 | - |
| LAB | Margaret Birleson | Hollybush | 02-05-2019 | - |
| LAB | Lynn Chesterman | Hollybush | 05-05-2022 | - |
| CON | Nick Pace | Hollybush | 07-05-2020 | - |
| LAB | Alan Chesterman | Howlands | 07-05-2020 | - |
| LAB | Max Holloway | Howlands | 05-05-2022 | - |
| LAB | Jill Weston | Howlands | 02-05-2019 | - |
| CON | George Michaelides | Northaw and Cuffley | 02-05-2019 | - |
| CON | Bernard Sarson | Northaw and Cuffley | 05-05-2022 | - |
| CON | Simon Anthony Wrenn | Northaw and Cuffley | 07-05-2020 | - |
| CON | Sara Glick | Panshanger | 02-05-2019 | - |
| CON | Terry Mitchinson | Panshanger | 07-05-2020 | - |
| LD | Ayesha Rohale | Panshanger | 05-05-2022 | - |
| LAB | Steve Roberts | Peartree | 02-05-2019 | - |
| LD | Malcolm Cowan | Peartree | 07-05-2020 | - |
| LD | Tamsin Francesa Jackson-Mynott | Peartree | 05-05-2022 | - |
| CON | Harry Bower | Sherrards | 07-05-2020 | - |
| CON | Patricia Mabbott | Sherrards | 02-05-2019 | - |
| LD | Jean-Paul Bernard Skoczylas | Sherrards | 05-05-2022 | - |
| LD | Helen Quenet | Welham Green and Hatfield South | 05-05-2022 | - |
| LD | Paul Zukowskyj | Welham Green and Hatfield South | 07-05-2020 | - |
| LD | Jaida Esin Caliskan | Welham Green and Hatfield South | 02-05-2019 | - |
| CON | Julie Cragg | Welwyn East | 07-05-2020 | - |
| CON | Steven Markiewicz | Welwyn East | 05-05-2022 | - |
| CON | Roger Trigg | Welwyn East | 02-05-2019 | - |
| CON | Tony Kingsbury | Welwyn West | 02-05-2019 | - |
| CON | Sunny Thusu | Welwyn West | 05-05-2022 | - |
| CON | Paul R Smith | Welwyn West | 07-05-2020 | - |