The Anson by-election, 1981, was held in Singapore on 31 October 1981 to choose a representative for the constituency of Anson in Parliament. The by-election was won by the leader of the Workers' Party, J.B. Jeyaretnam, who defeated the candidate of the governing People's Action Party (PAP), Pang Kim Hin. The by-election marked the first occasion since Singapore's independence in which a PAP candidate was defeated in an election for a seat in Parliament.