Roberts grew up in Abertillery, leaving school at the age of thirteen to work at a colliery.
He joined the South Wales Miners' Federation (SWMF), and won a union scholarship to attend the Central Labour College in 1919.
[1] In 1929 he finished second behind Aneurin Bevan in the contest to find a Labour candidate for the Ebbw Vale constituency.
In 1934, Roberts left the SWMF to become General Secretary of the National Union of Public Employees (NUPE).
[1] Roberts retired in 1962 due to increasingly poor health, and died two years later.