The Popular Socialist Party was a political party in Mexico. It was founded in 1948 as the Popular Party by Vicente Lombardo Toledano.

Vicente Lombardo Toledano was one of the foremost Mexican labor leaders of the 20th century, called "the dean of Mexican Marxism [and] the best-known link between Mexico and the international world of Marxism and socialism." In 1936, he founded the Confederation of Mexican Workers (CTM), the national labor federation most closely associated with the ruling party founded by President Lázaro Cárdenas, the Party of the Mexican Revolution (PRM). After he was purged from the union after World War II, Lombardo Toledano co-founded the political party "Partido Popular" along with Narciso Bassols, which later became known as the Partido Popular Socialista.