Walter Woon Cheong Ming (Chinese: 温长明; pinyin: Wēn Chángmíng; born 12 September 1956) is a Singaporean lawyer, academic, diplomat and politician. Educated at NUS and St. John's College, Cambridge, he joined the teaching staff of the NUS Faculty of Law in 1981 and later served as Sub-Dean and Vice-Dean. He was Legal Adviser to the President of Singapore and Council of Presidential Advisors from 1995 to 1997, and was appointed as professor of law in 1999.
Woon was a Nominated Member of Parliament between 1992 and 1996. He became the first Member of Parliament since 1965 to have a private member's bill become a public law in Singapore – the Maintenance of Parents Act, which was passed in 1995. Between 1997 and 2006, Woon served in a number of diplomatic capacities, including the Ambassador to Germany and the Ambassador to Belgium. He served as Attorney-General between 2008 and 2010. He is currently professor of law at the National University of Singapore's Faculty of Law and the Dean of the Singapore Institute of Legal Education.