The Radin Mas Constituency was a constituency in Singapore. It existed from 1976 to 1988.
The constituency was created prior to the 1976 general election; Govindasamy Naidu, the candidate for the governing People's Action Party (PAP), defeated Othman bin Abdullah from the Workers' Party (WP) with 75.65% of the vote.
In 1977, a by-election was called after Naidu died in office. Bernard Chen retained the constituency for the PAP, defeating J. B. Jeyaretnam, the secretary-general of the WP, with 70.59% of the vote. Syed Abu Bakar Alsagoff, an independent, had also attempted to contest the by-election; however, having not voted during the 1976 general election, he was disqualified after the end of nominations for being absent from the registers of electors.
During the 1980 general election, PAP candidate Mohamed Kassim Abdul Jabbar defeated WP candidate Wong Hong Toy with 64.07% of the vote. In the leadup to the 1984 general election, Lai Weng Cheong was announced as the PAP candidate but withdrew due to illness; he died of liver cancer on 30 October. He was replaced by Chng Hee Kok, who defeated Wong with 53.78% of the vote.
Prior to the 1988 general election, with the creation of group representation constituencies (GRCs), Radin Mas Constituency was abolished and made part of the three-member Tiong Bahru GRC.