Bellamy was born in Wigan, Lancashire and took up employment as an engine-driver for the London and North Western Railway.
He became involved in trade union activities, rising to the presidency of the Amalgamated Society of Railway Servants.
He made his home at Stockport, Cheshire, where he was president of the local Trades Council and Labour Party, as well serving as a magistrate.
[1] He eventually entered the Commons when he was elected Member of Parliament for Ashton-under-Lyne at a by-election in October 1928, after the sitting Conservative MP Cornelius Homan was disqualified when he was declared bankrupt.
Following the election, the Second Labour Government was formed, and he was appointed parliamentary private secretary to F O Roberts, Minister of Pensions.