He was born in Prahran, Melbourne on the 21st of October 1895, to Louis and Jane Aarons (née Hyam),[2] who passed on their radical politics to their son.

Sam joined the Australian Labor Party at the age of sixteen and was an anti-war campaigner during World War I.

This activism led to his sacking from his job at the Customs Department, and he was injured during a 1916 march to the Victorian Parliament.

Aarons fought in the Spanish Civil War on the republican side,[3] not leaving until the collapse of the Republic began in 1938.

[4] He remained active in communist affairs, but stood as an independent in the 1941 New South Wales state election for the western Sydney seat of Granville, where he only received 4.5%.