Juan Alejandro Barreto Cipriani (born 7 August 1959) is a Venezuelan politician and sociologist who served as mayor of Caracas from 2004 until 2008.

On July 30, 2000, Barreto was elected to the newly created National Assembly (the legislative body that replaced the Chamber of Deputies), receiving 276,952 votes, or 53.98% of the total votes, and represented the Venezuelan Capital District.

During his term in office, Barreto's relationships with the other mayors of Caracas were hostile.

On August 22, 2006 he denounced fellow mayors Leopoldo López and Henrique Capriles.

He was the director of the newspaper "Correo del Presidente", the Oficina Central de Información (OCI, now the Ministry of Communication and Information), and the news agency Venpres (now known as the Agencia Bolivariana de Noticias, or ABN).