The Gualeguaychú Department (in Spanish, Departamento Gualeguaychú) is an administrative subdivision (departamento) of the province of Entre Ríos, Argentina. It is located in the south-east of the province, beside the Uruguay River.

The department has 101,350 inhabitants as per the 2001 census [INDEC], which are distributed in 23 districts. The head town is Gualeguaychú (population 76,000). Other cities and towns are Aldea San Antonio, Larroque, Urdinarrain, Gilbert, Enrique Carbó, Pueblo General Belgrano, Irazusta, Costa Uruguay Norte, Aldea San Juan, Faustino M. Parera, General Almada, Las Mercedes, Cuchilla Redonda, Costa San Antonio, Rincón del Gato, Distrito Talitas, Alarcón, Estación Escriña, Costa Uruguay Sur, Pastor Britos, Perdices, and Rincón del Cinto.

• "Gualeguaychú Department" (in Spanish). Municipal Affairs Federal Institute (IFAM), Municipal Affairs Secretariat, Ministry of Interior, Argentina.