Harrow London Borough Council in London, England is elected every four years. Since the last boundary changes in 2022, 55 councillors are elected from 22 wards.
There were a total of 12 by-elections, including eight on 24 June 1964 caused by aldermanic elections.
The by-election was called following the resignation of Cllr Richard Denney.
The by-election was called following the death of Cllr Charles Green.
The by-election was called following the resignation of Cllr Ronald Grant.
The by-election was called following the resignation of Cllr Howard Cooper.
The by-election was called following the death of Cllr Leslie Nixon.
The by-election was called following the resignation of Cllr Derek Wiseman.
The by-election was called following the resignation of Cllr Brian Williams.
The by-election was called following the resignation of Cllr Norah Murphy.
The by-election was called following the resignation of Cllr Gareth Thomas.
The by-election was called following the resignation of Cllr Andrew Wiseman.
The by-election was called following the death of Cllr Alan Hamlin.
The by-election was called following the resignation of Cllr Tony McNulty.
The by-election was called following the death of Cllr Robert Lawrence.
The by-election was called following the death of Cllr Ann Swaine.
The by-election was called following the death of Cllr Antony Cocksedge.
There were no by-elections.
The by-election was called following the death of Cllr John Anderson.
The by-election was called following the death of Cllr Janet Cowan.
The by-election was called following the death of Cllr Dhirajlal Lavingia.
The by-election was called following the death of Cllr John Cowan.
The by-election was called following the resignation of Cllr Mark Versallion.
The by-election was called following the resignation of Cllr Brian Gate.
The by-election was called following the resignation of Cllr Ann Gate.
The by-election was caused by the death of Cllr Bob Currie
The by-election was caused by the death of Cllr Mitzi Green
The by-election was caused by the death of Cllr Chris Mote