Gerardus Johannes Geers (10 December 1891 in Delft – 2 May 1965 in Groningen), was a Dutch linguist and Hispanist.
Under the pseudonym of Cayo Graco he published articles in socialist periodics like Nuestra Palabra and El Comunista.
Despite his diplomatic immunity as part of the household of the envoy he was expelled from Spain for alleged "subversive activities".
He translated Miguel de Cervantes, Unamuno, Ortega y Gasset and Diez del Corral.
As an hispanist he criticized the popular "Leyenda negra" and he defended King Philip II of Spain against the many accusations.