Ringholm was born in Falköping, a town in the west of Sweden, and grew up in a working-class family. He lacks higher education, and dropped out of high school after failing both Maths and English. Like many Swedish Social Democratic politicians of his generation, Ringholm started his political career in the Swedish Social Democratic Youth League, an organisation he led 1967–1972. As chairman of the Social Democratic Youth League, Ringholm was known for his radical left-wing views. Among other things, he advocated the nationalization of private-owned Swedish bank institutions and Swedish economic support to the National Front for the Liberation of South Vietnam (FNL), the government of North Vietnam, the Pathet Lao in Laos and the Khmer Rouge in Cambodia.