A special election was held in New South Wales to fill the vacancy caused by the resignation of Liberal Senator Sir William Spooner.
A special election was held in Queensland to fill the vacancy caused by the death of Liberal Senator Bob Sherrington.
Bill Heatley, also of the Liberal Party, had been appointed to this vacancy in the interim period.
Edwin Ryan (LRG) Two special elections were held in Western Australia to fill the vacancies caused by the deaths of Liberal Senators Sir Shane Paltridge and Seddon Vincent.
Peter Sim and Reg Withers, both also of the Liberal Party, had been appointed to these vacancies in the interim period.