The Socialist Party (Spanish: Partido Socialista, PS), also known as Socialista Obrero (Socialist Worker's), was a pro-statehood political party in Puerto Rico, that also contemplated independence in the case that entry into the American Union was denied by Congress.

[1] The party was concerned with improving the social welfare of Puerto Ricans.

It was founded on 18 July 1899 as the Labor Party (Partido Obrero), and was also known as the Socialist Worker's Party (Spanish: Partido Obrero Socialista)[2] by Santiago Iglesias Pantín, an early leader of the Puerto Rican labor movement who was influenced by the Socialist Labor Party of America.

Over time, Iglesias and the Socialists became more in favor of statehood and worked with the pro-annexation Republican Party, joining them in an electoral alliance known as the Coalition which dominated island politics from 1932 to 1940.

The Socialists won seven seats to the island's constitutional convention, which convened between 1951 and 1952.