Guillaume Soisson (18 November 1866 – 27 August 1938) was a Luxembourgish engineer and politician for the Party of the Right.
A conservative, Soisson entered the cabinet of Hubert Loutsch in 1915 as the Director-General for Public Works and Director-General of Agriculture.[1] He resigned, along with the Prime Minister, on 24 February 1916.[2] He entered the cabinet for the second time, under Émile Reuter, as the Director-General for Public Works: replacing Guillaume Leidenbach, who had resigned on 14 April 1923.[3]