Adrian Tan Cheng Bock[1][a] (Chinese: 陈清木; pinyin: Chén Qīngmù; Pe̍h-ōe-jī: Tân Chheng-bo̍k; born 26 April 1940) is a Singaporean politician and physician.

After leaving the PAP, Tan founded the Progress Singapore Party (PSP), serving as secretary-general between 2019 and 2021 and as chairman since 2021.

[3] 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%.

Firmly believing in the value of diverse perspectives and the importance of giving Singaporeans a voice in the nation’s governance, he established the first governmental feedback unit, now known as REACH, in 1985.

[7] He left politics ahead of the 2006 general election, while his constituency was redrawn to the nearby West Coast GRC (Ayer Rajah division has since held by S Iswaran (which was absorbed alongside Iswaran's West Coast), and later Foo Mee Har since the 2011 general election).

Chief argument against the idea was that the use of such retirement savings may leave the account holder with an insufficient amount at the end of his or her working life.

[8] The set of guidelines on the use of CPF for Education proposed by the GPC was eventually implemented, paving the way for the beginnings of a wave of Singaporean students studying at local tertiary institutions.

[11] Tan voted against his own party, despite the Whip not having been lifted, regarding the NMP scheme, on the grounds that MPs had to be elected by the people and be accountable to an electorate for their views.

Although not against this rationale, Tan argued that the Singapore government should tone down its calls for the recruitment of foreign talent and reassure Singaporeans that they came first,[13] which earned him strong rebuttals, including one from George Yeo and a stern rebuke from Lee Kuan Yew.

[24] Tan along with team members, Leong Mun Wai, Hazel Poa, Nadarajah Loganathan and Jeffrey Khoo contested at West Coast GRC in the 2020 Singaporean general election which contained his former ward of Ayer Rajah but narrowly lost to the incumbent People's Action Party with 48.31% of the vote.

[30] Ahead of the nomination day (due to be held on 17 August), despite anticipation for a strong contest against the other potential rivals who also announced their candidacy (former Deputy Prime Minister Tony Tan, and NTUC Income Chief Executive Officer Tan Kin Lian), he filed his applications on 22 July, and on 11 August, was one of the four candidates (the aforementioned three, plus former Singapore Democratic Party candidate Tan Jee Say) to be granted the Certificate of Eligibility, an item required to complete their nominations during Nomination Day.

It was revealed that in a Straits Times article dated back in 1987, Tan had spoken regarding the Singaporean government's controversial Operation Spectrum while he was in Parliament, which saw 22 young Roman Catholic church and social activists and professionals detained without trial.

[33] He addressed, in his capacity as Feedback Unit chief, that most Singaporeans had accepted the reasons of the government and the Internal Security Department for the detention.

He also proposed that the government and the Prime Minister's Office be separated as "this familiarity attracts unwanted suspicion of undue influence".

Tan also proposed an annual statement for greater transparency for Singaporeans to better understand the president's activities and ideas in unifying Singapore.

In a congratulatory Facebook post published on 13 September 2017, Tan said that the elected Halimah Yacob would assume "...the most controversial presidency in the history of Singapore.

[49] The election ended with a walkover after former Parliamentary Speaker Halimah Yacob became the sole candidate to be granted the Certificate of Eligibility, and was inaugurated on 14 September.