Casual vacancies in the Dewan Rakyat (House of Representatives) are filled through by-elections, which may occur when a member of the Dewan Rakyat dies, resigns or for some other reason. Under Article 54(1) of the Constitution of Malaysia, the Election Commission of Malaysia has to call a by-election within 60 days of the establishment of the casual vacancy. A by-election is not held when there are less than two years left in the Parliament's term, unless the Speaker notifies the Election Commission that the casual vacancy affects the majority of the governing party.
Brackets around a date indicate that the candidate was unopposed when nominations closed. These candidates were declared "elected unopposed" with effect from the date of the closing of nominations, and there was no need to hold a by-election.
Election for Malacca Selatan federal constituency and another 40 federal constituencies in Sabah and Sarawak were postponed from the scheduled date, 10 May 1969.
