The 1968 Kensington South by-election by-election was held in the Kensington South constituency of the House of Commons of the United Kingdom on 14 March 1968. The election was to fill a vacancy in the seat formerly held by Conservative MP William Roots, who resigned from Parliament in 1968 due to ill health.
The seat was considered a safe seat for the Conservatives ('as safe and solid as the red-brick Victorian blocks of flats', wrote "the Times"); at the 1966 general election Roots was elected with 65.1 percent of the vote and a majority of 14,631. Turnout was expected to be low as the constituency had a large transient population living in bedsits and flats.
The Conservative Sir Brandon Rhys-Williams, a management consultant, won the seat with 75.5 percent of the vote and a slightly reduced majority (13,747) on a much reduced turnout. The Liberal candidate Thomas Kellock, a QC who had fought the seat at the previous general election, came in a distant second, with Labour candidate Clive Bradley, a barrister and journalist, forced into third place and losing his deposit. There were two independent candidates who received the fewest votes: Sinclair Eustace, 37, a teacher of phonetics and a campaigner against aircraft noise, described by "The Times" as 'perhaps the most civilized and likeable' of all the candidates but with a platform very close to that of the Liberal Party; and William Gold, 45, an engineer and 'a Buddhist, anti-vivisectionist, periodic vegetarian and author of at least six unpublished novels' who had only just returned to the UK after living in Australia.
Results.
! scope="col" colspan="2" style="width: 130px"|Party
! scope="col" style="width: 17em"|Candidate
! scope="col" style="width: 5em"|Votes
! scope="col" style="width: 3.5em"|%
! scope="col" style="width: 3.5em"| ;templatestyles src="Template:Tooltip/styles.css" / ;±%
! colspan="3" style="text-align: right; margin-right: 0.5em" | Majority
! colspan="3" style="text-align: right; margin-right: 0.5em" scope=row | Turnout
! style="text-align:right;" | Swing
Notes.
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