The Office was established in accordance with the Sino-British Joint Declaration on the Question of Hong Kong and the Basic Law of the Hong Kong Special Administrative Region.

On 19 December 1984, the Sino-British Joint Declaration on the Question of Hong Kong was signed between China and the UK. The Chinese Government announced that it would resume the exercise of sovereignty over Hong Kong and establish the Hong Kong Special Administrative Region on 1 July 1997. The Region would enjoy a high degree of autonomy.

On 4 April 1990, the Basic Law of the Hong Kong Special Administrative Region was passed by China's National People's Congress. Article 13 of this Law stipulates that  "The Central People's Government shall be responsible for the foreign affairs relating to the Hong Kong Special Administrative Region. The Ministry of Foreign Affairs of the People's Republic of China shall establish an office in Hong Kong to deal with foreign affairs."

Preparations for establishing the Office began in 1995. On 1 July 1997, the Office was officially established and then Vice Premier of the State Council Qian Qichen attended its inauguration ceremony.