The Workers' Party of Singapore (新加坡工人党), often referred to simply as "The Workers' Party" or "WP") is a centre-left opposition political party in Singapore. The party currently has five elected seats in Parliament, with the party's Secretary-General Pritam Singh, Chairman Sylvia Lim, Chen Show Mao, Muhamad Faisal Manap and Low Thia Khiang serving as Members of Parliament (MPs) for Aljunied Group Representation Constituency, Png Eng Huat as the MP for the single-member constituency of Hougang. Since 2011, the Workers' Party has been the only opposition party in Singapore to have elected MPs in Parliament. Yaw Shin Leong served as the Member of Parliament for Hougang from the period after the 2011 general elections until he was expelled from the party on 15 February 2012 for a lack of accountability.
The Workers' Party was founded by Singapore's former Chief Minister, David Marshall, in 1957. In 1981, the party's then-leader J.B. Jeyaretnam became the first opposition MP to be elected to Parliament since Singapore's independence in 1965, when he defeated the candidate of the governing People's Action Party (PAP) at a by-election in the constituency of Anson. He was re-elected at the 1984 general election, but subsequently lost his seat in Parliament in 1986 following a conviction for falsely accounting the party's funds (a conviction Jeyaretnam always maintained was politically motivated). Worker's Party member Lee Siew Choh served as a Non-Constituency Member of Parliament (NCMP) from 1988 to 1991. At the 1991 general election, Low Thia Khiang was elected as MP for Hougang. He was re-elected at the 1997, 2001 and 2006 general elections. Jeyaretnam returned to Parliament as an NCMP from 1997 to 2001, and Sylvia Lim has also served as an NCMP for the party from 2006 to 2011 when she became an elected Member of Parliament.
In recent years, The Workers' Party's candidates have worn a uniform of light blue shirts while campaigning to represent the party's links with the blue collar workers.