Tan Cheng Bock

Adrian Tan Cheng Bock (born 26 April 1940) is a Singaporean former politician and physician who has served as the secretary-general of the Progress Singapore Party (PSP) between 2019 and 2021 and chairperson since 2021.

A former member of the governing People's Action Party (PAP), he was the Member of Parliament (MP) for Ayer Rajah Single Member Constituency (SMC) between 1980 and 2006. He left politics before the 2006 general election and later left the PAP in 2011 to contest in the 2011 presidential election, losing marginally with 34.85% of the vote to Tony Tan in a four-cornered fight.

In 2019, Tan founded the opposition Progress Singapore Party (PSP). The PSP did not win any seats in the 2020 or 2025 general elections; however, they were awarded two non-constituency MP seats in 2020 after their team for West Coast Group Representation Constituency (GRC), led by Tan himself, won 48.31% of the vote, the closest result in the general election. He announced his retirement from politics shortly after the 2025 general election, but has remained a PSP member.

Tan was born on 26 April 1940 in Singapore. He was the third child out of six children.

Tan attended Radin Mas Primary School and Raffles Institution (RI). He graduated from the University of Singapore in 1968 with a Bachelor of Medicine and Surgery.

When Tan was 16, his father, a clerk with the Singapore Harbour Board, died from tuberculosis. As the father was a member of the Singapore Harbour Union, the family was entitled to a benevolent fund of $28,000. However, the union refused to pay, claiming that the father was not a member, as he had failed to pay his subscription fee. After Tan found receipts proving otherwise and sought legal aid, the family received $14,000, half of the fund, from the union.

Tan started his first clinic, Ama Keng Clinic, in Lim Chu Kang in 1971. He has served as the Chairman of the Society of Private Practice, as a Council Member of the College of General Practitioners, as Committee Member on the Council of the Singapore Medical Association (SMA), as Chairman of the SMA Trust Fund, as board member of SMA's Ethics Committee, as SMA's Representative on the Ministry of Health's Committee on the Regulation of Medical Clinics, and as a part-time clinical teacher in general practice at the National University of Singapore.

Tan entered politics during the 1980 general election under the People's Action Party's banner, and became the Member of Parliament-elect for the Ayer Rajah SMC with a vote of 83%. Tan's subsequent election results with an average of 77% was perceived as one of the best-performing candidates in Singapore, with his best-ever score being his last election in 2001, with 88%.