A Chinese Singaporean, Yao was a civil servant before he entered politics. He served as the Deputy Director at the Ministry of Home Affairs from 1980–81, and the Deputy Director at the Ministry of Finance's Public Service Division from 1982–84. From 1984–86, he served at the Ministry of Community Development as the Deputy Directory and Head of the Feedback Unit. He was the Deputy Director at the Ministry of Communications and Information from 1986–88. In 1988, Yao became the Political Secretary to Goh Chok Tong, who was then Singapore's First Deputy Prime Minister. Yao was elected to Parliament at the 1991 general election as an MP for the Marine Parade Group Representation Constituency. He remained part of the PAP's team at the Marine Parade by-election in 1992, and was re-elected. Yao was made a Parliamentary Secretary at the Ministry of Defence in 1991. In 1994, he was promoted to Senior Parliamentary Secretary at the Ministry of Defence and Ministry of National Development. In 1994, Yao was publicly challenged by the leader of the oppositionSingapore Democratic Party, Dr Chee Soon Juan, to stand against him in a single member constituency at the next general election. This happened following a series of letters which Yao and Chee wrote to The Straits Times. Chee had initially written to the newspaper to respond to criticisms that Deputy Prime Minister Lee Hsien Loong had made of his book Dare to Change, and Yao then responded in his capacity as the PAP's Second Organising Secretary. This led to a two-month-long exchange of letters between the pair which were published in the paper, which ended with Chee issuing his challenge to Yao. At Yao's request, Prime Minister Goh Chok Tong agreed to separate Yao's MacPherson ward from the rest of the Marine Parade Group Representation Constituency at the next general election so that Yao could take up Chee's challenge. At the 1997 general election, Yao defeated Chee by 12,546 votes to 6,713. Yao was subsequently re-elected as the MP for MacPherson at the 2001 and 2006 general elections. After the 1997 general election, Yao was made a Minister of State at the Ministry of Defence. In 1999, he became a Minister of State at the Prime Minister's Office. He was promoted to Senior Minister of State in 2001. During his time at the Prime Minister's office, Yao also served as the Deputy Secretary General of the National Trades Union Congress. In 2004, Yao left the Prime Minister's Office to become the Mayor of the South East District of Singapore. He remained an MP, and in 2006 he was made a Deputy Speaker of Parliament alongside his role as Mayor. Prior to the 2011 general election, Yao announced that he was retiring from politics and would not be standing as a candidate. His MacPherson ward was subsumed back into the Marine Parade Group Representation Constituency for the election, and after the election responsibility for the ward was taken over by Tin Pei Ling, whom Yao had previously mentored.
Personal life
Yao is married with two children. His personal interests include reading, jogging and golf.
