Montague David Miller, born 7 July 1839 in Van Diemen's Land (present day Tasmania), was an Australian trade unionist, secularist, and revolutionary anarchist-socialist chiefly active in the states of Victoria and, in his most productive period, in Western Australia.
His activism with unions and the Industrial Workers of the World (IWW), during the early years of the twentieth century, saw him acting as a speaker and organiser for these sometimes illegal groups, leading to his conviction for conspiracy in 1916.
At the age of 15, Miller took part in the Eureka Rebellion – an uprising at Ballarat by self-employed miners, who were opposed to the policies of an authoritarian British colonial regime in Victoria.
Many of his friends and colleagues were to assist in his defence, including Annie Westbrook and Willem Siebenhaar (sacked and consequently charged), and this high-profile case was to have a significant impact on the socialist and union movements and to the conscription debate.
Miller was re-arrested in 1917 in Sydney at the age of 84 and sentenced to six months imprisonment with hard labour at Long Bay Gaol on the charge of belonging to an unlawful association.
Bitter post war divisions existed in Australia at that time, yet harassment by the media and suppression by conservative governments of political opposition did not dissuade Miller from promoting his revolutionary aims.