This was the only year in Singapore history where a third round of by-elections was held, after another spate of resignations by Barisan Members of Parliament. This time, they were officially sanctioned by Barisan for the purpose of boycotting Parliament and "struggle for democracy". Its remaining MPs would resign, starting with Chia Thye Poh and Lee Tee Tong on 7 October 1966. Chia would later be detained under the Internal Security Act for 22 years and become the world's second-longest political prisoner after South African Nelson Mandela. Also, PAP MP Dr Fong Kim Heng requested to step down due to poor health, which took effect on 18 October 1966. Once again, the seats were conceded to PAP via walkovers.

Writ of election: 27 October 1966 [Thu]
Nomination day: 2 November 1966 [Wed]
Members swearing-in: 5 December 1966 [Mon]

Electorate: 39,371

Election deposit: $500

Bukit Timah Joo Chiat Jurong

General Election 1963
By-Election 1965
By-Election January 1966
Previous: By-Elections March 1966
Next: By-Elections 1967
General Election 1968