Pedro Méndez Mercado (1902- ) was born in Ponce to Spanish immigrant José Méndez López and Yauco born Rosario Mercado Galarza. He graduated from the Ponce High School in 1920, he enrolled at Cornell University where he studied mechanical engineering for only one year. He then enrolled at the newly created Department of Architecture of the Colegio de Agricultura y Artes Mecánicas in Mayagüez. However the Architecture program was cancelled in 1924 when he then transferred to Syracuse University where he graduated in 1926 with a Bachelor's in Architecture.

He returned to Puerto Rico in 1926 where he worked at the Puerto Rico Public Buildings Authority. His first project as an architectural draftsman was the design of the Guayama Fire station. In 1932 he returned to Ponce with his wife Celia Gómez and their newborn baby to work in the private sector. In 1935 he returned to San Juan where he was briefly employed at the Puerto Rico Emergency Relief Administration (PRERA) and later worked as inspector during the construction of the Casa de España. There, he met Pedro Adolfo de Castro with whom he developed a close professional relationship.

While in San Juan, in 1935 Mendez was commissioned the design of the Miami Apartments Building , however, due to the death of his father in January 1936 and that of de Castro in October of the same year, Mendez returned to Ponce in 1937 where he remained until 1941. While in Ponce, he worked on the design of the remodeling of Plaza de Mercado Isabel II in 1941 and the design of the apartment building known as Apartamentos Beatriz. In 1941 he returned to San Juan to work for the United States Department of the Interior, first as superintendent during the construction of the Puerto Rico Capitol and later as chief in the Puerto Rico Public Buildings Authority.

After the end of WWII, he returned to Ponce, where he established a private practice and worked for various government agencies. He is credited with the design of most of the Art Deco theaters in Ponce built during this time. After he retired from public service, Méndez continued his private practice until his retirement in 1982.