Baron Charles Jean Maurice Lemonnier (12 January 1860 – 11 September 1930) was a Belgian liberal politician and mayor of the City of Brussels. Charles Lemonnier was a lawyer, mining engineer and as a politician he was alderman ad-interim burgomaster of Brussels. He was also a member of parliament. During World War I he took over as burgomaster of Brussels, while Adolphe Max was held in captivity by the Germans.