This was the year's third round of by-elections and the only year in Singapore history with three, after another spate of resignations by BS Members of Parliament. This time, they were officially sanctioned by BS for the purpose of its boycott of Parliament and "struggle for democracy". All its remaining nine MPs resigned, 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 incarcerated political prisoner. On top of this, PAP MP Dr Fong Kim Heng stepped down and retired due to poor health. All the resignations took effect on 18 October 1966. Once again, the contested 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]

Eligible voters: 39,371

Election deposit: $500

RESULTS
Bukit Timah	Joo Chiat	Jurong
Total seats = 3