Sir Mark Aitchison Young GCMG KStJ (Chinese: 楊慕琦; 30 June 1886 – 12 May 1974) was a British colonial administrator, who is best remembered for his service as the Governor of Hong Kong at the time of the Japanese invasion of the territory in 1941.

Born in British India, the son and grandson of senior members of the Indian Civil Service, Young followed in the steps of his two elder brothers and became a colonial administrator, serving in Ceylon, Sierra Leone, Palestine, before becoming Governor of Barbados and of Tanganyika.

During the Battle of Hong Kong, Young refused to capitulate on numerous occasions, before surrendering on Christmas Day, 1941 in order to avoid further bloodshed.

With the war in Europe looming, Young restored confidence within the colony, which was apprehensive that it would be returned to Germany as part of peace negotiations.

He was initially held in the Peninsula Hotel and subsequently incarcerated in a prisoner of war camp in Stanley, on the southern shores of Hong Kong Island.

After returning, he proposed political reforms that would have allowed Hong Kong residents to directly choose a 30-member representative Legislative Council.

Young, echoing the plan of Sir Geoffry Northcote, called for the promotion of local Chinese civil servants to the senior posts.

Young, Sir William Robinson and Christopher Patten are the only governors not to have been honoured in Hong Kong after completing their post.