In the reflection of Benjamin Constant, political economy occupies an important place, which has rarely received the attention it deserves. The aim of this essay is to analytically reconstruct this reflection as Constant developed it in his Principes de politique (1806) and in Commentaire à Filangieri and to answer to the following questions: what kind of relationship Constant has with the current thought on political economy? What place did economic freedom occupy in his wider belief system? Did the social question have any bearing on Constant’s economical beliefs?