thumb|160px|Count Nicolas Ménager
Nicolas Mesnager (or Le Mesnager or Ménager) (1658–1714) was a French diplomat.
thumb|right|100px|Breast Star of Knight of Malta
Le Mesnager belonged to a wealthy merchant family, forsaking a commercial career, to become a parliamentary lawyer for Rouen under the Ancient régime. In 1700 he was sent as Rouen's Advocate-Deputy to the Council of Commerce held in Paris convened to promote trade agreements for France. At Versailles he made his mark, thereafter being nominated to go on three missions to Spain, between the years 1704 and 1705, to negotiate financial arrangements. In Spain he was appointed harbourmaster of Cádiz and he helped improve trade with the Spanish colonies.
In August 1711 he was sent on a secret mission to London to detach Great Britain from its alliance against France, and succeeded in securing the adoption of eight articles which formed the base of the later Treaty of Utrecht.