Guayama is a municipality

Municipality

A municipality is essentially an urban administrative division having corporate status and usually powers of self-government. It can also be used to mean the governing body of a municipality. A municipality is a general-purpose administrative subdivision, as opposed to a special-purpose district...

 of Puerto Rico

Puerto Rico

Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...

 founded on January 29, 1736 and located on the Southern Coastal Valley region, bordering the Caribbean, south of Cayey

Cayey, Puerto Rico

Cayey is a mountain town in central Puerto Rico located on the Central Mountain range, north of Salinas and Guayama; south of Cidra and Caguas; east of Aibonito and Salinas; and west of San Lorenzo Cayey is spread over 21 wards and Cayey Pueblo...

; east of Salinas

Salinas, Puerto Rico

Salinas is a small municipality in the southern part of Puerto Rico located in the southern coast of the island, south of Aibonito and Cayey; southeast of Coamo, east of Santa Isabel; and west of Guayama...

; and west of Patillas

Patillas, Puerto Rico

Patillas is a municipality of Puerto Rico located in the southeastern coast, south of San Lorenzo; west of Yabucoa and Maunabo; and east of Guayama and Arroyo. It is spread over 15 wards and Patillas Pueblo...

 and Arroyo

Arroyo, Puerto Rico

Arroyo is a municipality located along the southern coast of Puerto Rico and bordered by the Caribbean Sea, east of the municipality of Guayama and northwest of the municipality of Patillas. Arroyo is spread over 5 wards and Arroyo Pueblo...

. Guayama is spread over 9 wards and Guayama Pueblo (The downtown area and the administrative center of the city). It is the principal city of the Guayama Metropolitan Statistical Area.

According to the 2010 census

United States Census Bureau

The United States Census Bureau is the government agency that is responsible for the United States Census. It also gathers other national demographic and economic data...

, the city has a population of 45,362.
The town was founded on January 29, 1736 as San Antonio de Padua de Guayama by Matías de Abadía, although there is knowledge of it being populated by native Indians as early as 1567.