Peñuelas (Spanish pronunciation: [peˈɲwelas], locally [peˈɲwelaʔ]) is a town and municipality in Puerto Rico located in the Peñuelas Valley on the southern coast of the island, south of Adjuntas, east of Guayanilla, west of Ponce and north of the Caribbean Sea. Peñuelas is spread over 12 barrios and Peñuelas Pueblo (the downtown area and the administrative center of the city). It is part of the Yauco Metropolitan Statistical Area. Peñuelas is known as "La Capital del Güiro" (The Güiro Capital) and "El Valle de los Flamboyanes" (The Valley of the Royal Poinciana trees). In 2020, Peñuelas had a population of 20,399.

In 1754, a group of workers had settled over the Bay of Tallaboa. Later gradually retreated deeper into the valley, heading to the most fertile land which would then be part of the town of Peñuelas. For the year 1788, approximately 80 families inhabiting the valley, which focused mainly on agriculture and livestock. Peñuelas Township was founded August 25, 1793 by Diego de Alvarado.

By 1874, the town had been developed and had a population of 9,206, according to a census of that year. The town had four main roads, some streets, a brick church and the town hall, which also served as a prison, barracks and a cemetery.

On March 1, 1902 the Legislative Assembly of Puerto Rico approved a law to consolidate certain municipal districts, so Peñuelas neighborhoods were attached to the municipality of Ponce. In 1905, the same Assembly repealed the law and Peñuelas became once again a municipality.

The first incident of the Puerto Rican Nationalist Party Revolt of 1950 occurred during the early hours of October 29, 1950 in Peñuelas when the insular police of that town surrounded the house of the mother of Melitón Muñiz Santos, the president of the Peñuelas chapter of the Nationalist Party in the barrio Macaná, under the pretext that he was storing weapons for the Nationalist Revolt. Without warning, the police fired upon the Nationalists in the house and a firefight between both factions ensued, which resulted in the death of two Nationalists and the wounding of six police officers. Nationalists Melitón Muñiz Santos, Roberto Jaume Rodríguez, Estanislao Lugo Santiago, Marcelino Turell, William Gutiérrez and Marcelino Berríos were arrested and accused of participating in an ambush against the local insular police.

On September 20, 2017 Hurricane Maria struck the island of Puerto Rico. In Peñuelas, an estimated 1,500 homes were completely destroyed and 500 were partially destroyed. With its winds and rainfall, the hurricane triggered numerous landslides in northern Peñuelas.

Peñuelas is located on the southern coast, slightly west of the center.

Rivers near Peñuelas include: