Olt is a river in Romania. Its source is in the Hăşmaşu Mare Mountains of the eastern Carpathian Mountains. It flows through the Romanian counties Harghita, Covasna, Braşov, Sibiu, Vâlcea and Olt.

Known as river Alutus in Roman Antiquity.

The cities Miercurea Ciuc, Sfântu Gheorghe, Făgăraş, Râmnicu Vâlcea and Slatina lie on the river Olt. The Olt flows into the river Danube near Turnu Măgurele.