Sir William Addis, KBE, CMG (5 September 1901 – 19 November 1978) was a British colonial administrator.
During his tenure as governor, he was responsible for Archbishop Makarios, who had been exiled to the colony from Cyprus.
He entered the Colonial Administrative Service in 1924, and subsequently served in Zanzibar and Northern Rhodesia, with a secondment to the Dominions Office during 1933.
From 1950 to 1953, he was based in Singapore as Deputy Commissioner-General for Colonial Affairs, South-East Asia, in succession to Sir Ralph Hone.
During his tenure, Addis was responsible for Archbishop Makarios, who had been exiled to the Seychelles from Cyprus.