Robert Samuel Ross (5 January 1873 – 24 September 1931) was an Australian socialist journalist, trade unionist, and agitator best known as the editor of a series of political magazines associated with the Australian labour movement in the 1890s and early 1900s.
Ross' militant journalism and agitation against Australia's involvement in World War I led to repression by the authorities. Ross' works during the war were censored and confiscated by the police and Ross faced multiple arrests for opposing conscription, waving the socialists' red flag, and circulating anti-war literature. His publication of the article "Bolshevism Has Broken Out in Heaven" led to a 1919 trial for blasphemy.
Ross' political views were drastically moderated during the 1920s. His contributions to Australian political life ended with his death as a respected member of the Australian Labor Party in 1931.