Before (end of 2017) (58 seats, Elections Centre)
Conservative 31 · Liberal Democrats 17 · Labour 7 · Other 3
After (end of 2018) (58 seats, Open Council Data)
Conservative 30 · Liberal Democrats 18 · Labour 6 · Other 3 · Green 1
Ward results
Ashley1 seat · turnout 41.5%
| Anthony Rowlands | Liberal Democrats | 1,407 ✓ |
| Jagat Chatrath | Labour | 557 |
| John Stephen Whale | Conservative | 326 |
| Stephane Antoine Farenga | Green | 145 |
Batchwood1 seat · turnout 45.7%
| Roma Mills | Labour | 1,238 ✓ |
| Liz Needham | Liberal Democrats | 576 |
| Nadine Standish | Conservative | 508 |
| Lucy Swift | Green | 146 |
Clarence1 seat · turnout 44.7%
| Caroline Brooke | Liberal Democrats | 1,370 ✓ |
| Patti Seabright | Conservative | 533 |
| Alexander Veitch | Labour | 308 |
| Mary Clare Henry | Green | 159 |
Colney Heath1 seat · turnout 35.8%
| Jamie Day | Liberal Democrats | 853 ✓ |
| David Michael Johns | Conservative | 434 |
| Eileen Francis | Labour | 242 |
| Thomas Langton | Green | 78 |
Cunningham1 seat · turnout 43.8%
| Robert Prowse | Liberal Democrats | 805 ✓ |
| Muhammad Abdur Rahim | Labour | 596 |
| Sarah Tallon | Conservative | 544 |
| Phil Fletcher | Green | 105 |
| Alan Robert Malin | UK Independence Party (UKIP) | 78 |
Harpenden East1 seat · turnout 36.1%
| Mary Maynard | Conservative | 1,048 ✓ |
| Guy Cozon | Liberal Democrats | 604 |
| James Nathaniel Gill | Labour | 361 |
Harpenden North1 seat · turnout 34.5%
| Paul Cousin | Conservative | 982 ✓ |
| Melanie Priggen | Liberal Democrats | 586 |
| Linda Ann Spiri | Labour | 241 |
| Ian Troughton | Green | 116 |
Harpenden South1 seat · turnout 38.3%
| Teresa Heritage | Conservative | 1,322 ✓ |
| Zoe Galvin | Liberal Democrats | 350 |
| George Murray Fraser | Labour | 274 |
| Sally Leonard | Green | 111 |
Harpenden West1 seat · turnout 40.5%
| Julian Daly | Conservative | 1,377 ✓ |
| Alison Woodley | Liberal Democrats | 553 |
| Michael Philip Gray-Higgins | Labour | 313 |
| Candy Whittome | Green | 125 |
London Colney1 seat · turnout 34.0%
| Katherine Gardner | Labour | 963 ✓ |
| Robert Anthony Dunster | Conservative | 784 |
| Tony Lillico | Liberal Democrats | 394 |
| Chris Flynn | Independent | 171 |
| Matthew Maddock | Green | 110 |
| Charles Michael Mason | UK Independence Party (UKIP) | 56 |
Marshalswick North1 seat · turnout 59.4%
| Thomas Clegg | Liberal Democrats | 1,014 ✓ |
| Claudio Duran | Conservative | 779 |
| Mary Winifred McIntyre | Labour | 307 |
| Dee Thomas | Green | 127 |
Marshalswick South1 seat · turnout 49.3%
| Helen Rosemary Campbell | Liberal Democrats | 1,113 ✓ |
| Craig Steven Fothergill | Conservative | 927 |
| Jon Pearce | Labour | 453 |
| Jill Mills | Green | 146 |
| Susan Devi | Independent | 60 |
Park Street1 seat · turnout 39.7%
| Simon Nash | Conservative | 1,008 ✓ |
| Syed Abidi | Liberal Democrats | 918 |
| Janet Blackwell | Labour | 282 |
| Rosalind Mary Paul | Green | 84 |
Redbourn1 seat · turnout 36.7%
| Victoria Mead | Conservative | 1,096 ✓ |
| Anthony Eric Neville | Labour | 330 |
| Chris Brattle | Liberal Democrats | 223 |
| Ruth Farenga | Green | 135 |
Sandridge1 seat · turnout 41.0%
| Beric Read | Conservative | 786 ✓ |
| Stefania Estacchini | Liberal Democrats | 332 |
| Jon Hegerty | Labour | 245 |
| James Richard Lomas | Green | 172 |
Sopwell1 seat · turnout 46.8%
| Shakir Rahman | Liberal Democrats | 1,234 ✓ |
| Iain Grant | Labour | 834 |
| Heather Rench | Conservative | 331 |
| Frankie Drummond Charig | Green | 103 |
St Peters1 seat · turnout 43.1%
| Jacqui Taylor | Liberal Democrats | 849 ✓ |
| Keith Michael Cotton | Green | 786 |
| Alun Davies | Conservative | 721 |
| Mark Antony Ewington | Labour | 341 |
St Stephen1 seat
| Sue Featherstone | Conservative | 1,367 ✓ |
| Alison Ross | Liberal Democrats | 473 |
| Heather Jane Troy | Labour | 212 |
| Mark Stephen Charles Park-Crowne | Green | 100 |
Verulam1 seat · turnout 50.4%
| Edward Hill | Liberal Democrats | 1,593 ✓ |
| Nicholas Paul Verity | Conservative | 858 |
| Gordon Baisley | Labour | 257 |
| Josie McNally | Green | 113 |
Wheathampstead1 seat · turnout 39.5%
| Annie Brewster | Conservative | 1,297 ✓ |
| Andrew Crofts | Liberal Democrats | 281 |
| Neill Sankey | Labour | 238 |
| Oliver Hitch | Green | 147 |