Flix is a town in the comarca of Ribera d'Ebre, in the Catalonia region of Spain. It is situated on a promontory beside the Ebro river, a position that gave the town an important strategic role.
The town lies on the Madrid–Barcelona railway line. During the early twentieth century it expanded, a growth linked to the construction of a hydroelectric power station in 1948 and to a large chemical plant, Electroquímica de Flix.