Ilhéus (ēlyĕˈōs) [key], city (1991 pop. 223,750), Bahia state, E Brazil, a port on Ilhéus Bay, an inlet of the Atlantic Ocean. Founded in the mid-16th cent., it became the world's chief cacao port during the early 20th cent. Ilhéus is still the cacao center of Brazil. It exports rubber, timber, chemicals, and piassava. A hydroelectric project is located north of Ilhéus.