Anson Maria Elizabeth Chan Fang On-sang, is a retired Hong Kong politician and civil servant who was the first ethnic Chinese and woman to serve as Chief Secretary, the second-highest position in both the British colonial government and the Hong Kong SAR government under the Chinese sovereignty from 1993 until she retired from the government in 2001, sparking speculations of her growing rift with Chief Executive Tung Chee-hwa.

The Chief Secretary for Administration, commonly known as the Chief Secretary of Hong Kong, is the most senior principal official of the Government of the Hong Kong Special Administrative Region. The Chief Secretary is head of the Government Secretariat which oversees the administration of the Region to which all other ministers belong, and is accountable for his or her policies and actions to the Chief Executive and to the Legislative Council. Under Article 53 of the Basic Law, the position is known as "Administrative Secretary". As the second highest ranking public official in Hong Kong, the Chief Secretary acts as Acting Chief Executive when the Chief Executive is absent.