The Socialist Party (Swedish: Socialistiska partiet), was a political party in Sweden active from 1929 to 1948. Led by Karl Kilbom and Nils Flyg, the party was founded in 1929 as a splinter group of the Communist Party of Sweden. Until 1934, the splinter group used the same name Communist Party of Sweden (Swedish: Sveriges kommunistiska parti), so in order to keep the two factions apart, this faction was generally known as Kilbommare ("Kilbomiars") while those who stayed in the old party were known as Sillénare ("Sillénians", after their leader Hugo Sillén).