The Puerto Rican Independence Party (Spanish: Partido Independentista Puertorriqueño, PIP) is a social-democratic political party in Puerto Rico that campaigns for the independence of Puerto Rico from the United States.

Those who follow the PIP ideology are usually called independentistas, pipiolos or pro-independence activists.

The party began as the electoral wing of the Puerto Rican independence movement. It is the largest of the independence parties, and the only one that is on the ballot during elections (other candidates must be added in by hand). In 1948, two years after being founded, the PIP gathered 10.2% of the votes in the island. In 1952, two years after an armed uprising of the Puerto Rican Nationalist Party, it obtained 19% of the votes, its highest electoral support ever, which made it the second electoral party on the island for a moment. In 1956 it took 12.4% of the votes; in 1960 3.1%; in 1964, 4%; in 1968, 3.5%; in 1972, 5.4%; in 1976, 5.7%; in 1980, 5.4%; in 1984, 3.6%, and in 1988, 5.5%. In 2004 it obtained 2.7% of the votes, and in 2008 it took 2%.

The party was founded on 27 October 1946, by Gilberto Concepción de Gracia (1909–1968), his colleague Fernando Milán Suárez and Antonio J. González. They felt the independence movement had been betrayed by the Popular Democratic Party, whose ultimate goal had originally been independence.

Former FBI Director Louis Freeh admitted 2003 in a congressional budget hearing that the FBI had engaged in suppression of Puerto Rican independence groups from the 1930s to the 1990s, including surveillance of the Puerto Rican Independence Party. The actions undertaken by the FBI have been described as "egregious illegal action, maybe criminal action."

After Freeh's public admission, The New York Times reported the following details about actions against the Puerto Rican Independence Party:

They include a 1961 directive from Mr. Hoover to seek information on 12 independence movement leaders, six of them operating in New York, "concerning their weaknesses, morals, criminal records, spouses, children, family life, educational qualifications and personal activities other than independence activities." The instructions were given under the domestic surveillance program known as COINTELPRO, which aimed at aggressively monitoring antiwar, leftist and other groups in the United States and disrupting them.

In the case of Puerto Rican independence groups, J. Edgar Hoover's 1961 memo refers to 'our efforts to disrupt their activities and compromise their effectiveness.' Scholars say the papers provide invaluable additions to the recorded history of Puerto Rico. "I expect that this will alter somewhat the analysis of why independence hasn't made it,' said Félix V. Matos Rodríguez, director of the center at Hunter. 'In the 1940s, independence was the second-largest political movement in the island, (after support for commonwealth status), and a real alternative. But it was criminalized.'