He was a member of the Melo de Portugal family, a minor branch of the Portuguese House of Braganza.

Pedro de Melo served in many military roles in Spain before moving to South America in 1770.

He was member of the Real Audiencia and worked for the creation in 1794 of a Royal Counsel with viceroy Nicolás Antonio de Arredondo.

He kept the main policies of previous viceroys: improve the streets of Buenos Aires, or fortified defenses for Montevideo, but he had to face Portuguese incursions on the Banda Oriental.

He created laws to deal with the shortage of bread, improved the viceroyal residence, and received ships from the Pacific Ocean.