William Sydney Marchant CMG OBE (10 December 1894 – 1 February 1953) was a British colonial administrator.
Marchant became an Assistant District Commissioner in East Africa Protectorate in 1919.
In 1926 he was promoted to District Officer in Kenya, and then became Deputy Provincial Commissioner and Assistant Secretary in Zanzibar in 1935.
On Malaita he helped operate a coastwatcher radio relay station in support of the Allied Solomon Islands campaign until the end of his appointment in 1943.
This article about a person involved in governance in the United Kingdom or its predecessor states is a stub.