Fernand Charles Gustave Demets (French: [d?m?]; 8 March 1884 – 29 September 1952) was a Belgian liberal politician, burgomaster, and defense minister.
Demets was an industrialist and became a municipal council member (1911–1929) and burgomaster (1919–1927) in Anderlecht, then a Liberal senator (1929–1945) in the district of Brussels.
Demets was co-president of the Liberal Party (1940–1945).
He was minister of defense in 1944-1945 and afterwards became governor of the province of Brabant (1945–1951).