He attended St Paul's School and Magdalen College, Oxford, where he studied Sanskrit and the classics.

After serving as an Assistant Registrar General in 1901, Clementi joined as a member of the Board of Examiners in Chinese, in 1902.

While he was in that position, Clementi represented the Hong Kong government in the International Opium Conference at Shanghai, in 1909.

Clementi eventually became Acting Colonial Secretary and Member of both the Executive and Legislative Councils of Hong Kong.

[2] In 1925, Clementi was appointed as Governor of Hong Kong, a position to which his fluency in Cantonese suited him well and in which he served until 1930.

[citation needed] He also notably ended the practice of Mui Tsai, the traditional Chinese "female maid servitude" system which often resulted in the abuse of young servant girls.

[citation needed] He also appointed Shouson Chow, a prominent Chinese merchant, as the first unofficial member of the Executive Council.

At the same time, he increased the numbers of official and non-official ("Unofficial") members in the Legislative Council from eight to ten (including the Governor) and from six to eight, respectively.

[7] He handed over to Sir Andrew Caldecott, who become acting Governor, and left for England due to his illness.