Historical José Guilherme Merquior (April 22, 1941 – January 7, 1991) was a Brazilian diplomat, academic, writer, literary critic and philosopher.

He was a prolific writer, and member of the Academia Brasileira de Letras (the Brazilian Academy of Letters).

He had a doctorate in sociology from the London School of Economics, which was directed by Ernest Gellner.

He published books written directly in French, English, Italian, and his native Portuguese.

In one the bulk was criticism per se; in the other the emphasis was the history of ideas, or more specific investigations like the highly esteemed study of Jean-Jacques Rousseau and Max Weber.