Yeo worked for Singapore's
Economic Development Board (EDB) from 1972 to 1975, before entering the private sector. He entered politics in 1984. At the
1984 general election, Yeo was elected a Member of Parliament for Hong Kah Constituency. In 1985, he was appointed a Minister of State at the
Ministry of Health and
Ministry of Foreign Affairs. In 1988, Yeo became the Acting
Minister for Health, before becoming a full member of the Cabinet in 1990. He went on to hold a number of different Cabinet positions including
Minister of Health (1990–94, 1997–99),
Minister for Community Development (1991–94),
Minister for Trade and Industry (1994–97),
Minister for the Environment (1997–99),
Minister for Communications and Information Technology (1999–2001), and
Minister for Transport (2001–06). In June 2006, after the announcement of the new
Cabinet of Singapore,
Prime Minister of Singapore Lee Hsien Loong said Yeo had intended to retire from politics but had persuaded him to continue as an MP after stepping down from the Cabinet. He continued to serve as a Member of Parliament for the
Hong Kah Group Representation Constituency until 2011, when he retired from politics. ==Personal life==