The Chefoo Convention, known in Chinese as the Yantai Treaty, was an unequal treaty between Britiain and Qing China, signed by Sir Thomas Wade and Li Hongzhang in Chefoo (now a district of Yantai) on 21 August 1876.
The convention settled the Margary Affair in exchange for expanded commercial concessions to Britain.
The second section dealt with official intercourse between the two empires and specified the extraterritorial privileges of British subjects in China.
One practical result of the treaty was that the official mission of apology to Britain, led by Guo Songtao, became a permanent diplomatic mission in Britain, opening the way for a permanent foreign representation of China.
The Chefoo Convention was ratified immediately by the Qing government, but was not ratified by Britain until July 1885, due to criticism and opposition from British opium merchants in Calcutta and Bombay, as well as from the government of the British Raj.