| Election Name: | 1957 Singaporean by-elections |
| Country: | Singapore |
| Flag Year: | 1957 |
| Flag Image: | Flag of Singapore (1952–1959).svg |
| Type: | legislative |
| Vote Type: | popular |
| Election Date: | 29 June 1957 |
| Previous Election: | 1952 Seletar by-election |
| Previous Year: | 1952 |
| Next Election: | 1961 Singaporean by-elections |
| Next Year: | 1961 |
| Seats For Election: | 2 seats to the Legislative Assembly of Singapore |
| Registered: | 29,563 |
| Turnout: | 12,874 (43.55%) 11.16% |
| Leader1: | Lee Kuan Yew |
| Party1: | People's Action Party |
| Seats1: | 1 |
| Popular Vote1: | 4,707 |
| Percentage1: | 36.99% |
| Swing1: | 4.18% |
| Image2 Size: | 150x150px |
| Leader2: | Tan Chye Cheng |
| Party2: | Liberal Socialist Party (Singapore) |
| Seats2: | 1 |
| Seat Change2: | 1 |
| Popular Vote2: | 3,657 |
| Percentage2: | 28.74% |
| Swing2: | 7.52% |
| Image3 Size: | 150x150px |
| Leader3: | Lim Yew Hock |
| Party3: | Labour Front |
| Seats3: | 0 |
| Seat Change3: | 1 |
| Popular Vote3: | 1,118 |
| Percentage3: | 8.79% |
| Swing3: | 13.78% |
| Image4 Size: | 150x150px |
| Party4: | Malay Union |
| Seats4: | 0 |
| Popular Vote4: | 983 |
| Percentage4: | 7.73% |
| Swing4: | 7.73% |
| Assemblymen | |
| Posttitle: | Elected Assemblymen |
A by-election was held on 29 June 1957, with nomination day occurring on 18 May 1957 in the Cairnhill, and Tanjong Pagar constituency. When talks with the British authorities for self-governance broke down, Chief Minister David Marshall decided to resign from the Labour Front on 7 June 1956. Marshall had also challenged opposition leader Lee Kuan Yew from the People's Action Party to resign and recontest his Tanjong Pagar constituency as well, which he did.
The Labour Front's replacement candidate Keng Bang Ee lost the seat to the new Liberal Socialist Party, while Lee retained his seat in Tanjong Pagar.
The by-election had a voter turnout of merely 43.55%, the lowest of any elections during the period between 1948 and 1959. With the introduction of compulsory voting in 1959, the turnout of 43.55% remains the lowest for any elections in Singapore's history.
The election deposit was stated at $500.
Note 1: As Mirza Abdul Majid had failed to secure 12.5% of the votes, he had his election deposit forfeited.
Note 2: In 1957, Singapore Malay Union (SMU) was expelled by its alliance partners consisted of UMNO and MCA for fielding a candidate in this by-election which was the reason for the elections department of Singapore to view Tengku Muda as another independent candidate.