A. G. Stephens was born and educated in Toowomba, Queensland. After a typographical appenticeship in the 1880s, he moved to Gympie where he took over the editorship of The Gympie Miner and was an active participant in local literary discussions. In 1890 he became the sub-editor and writer for the radical Boomerang in Brisbane, them joined the Cairns Argus in late 1891, eventually becoming part-owner. In late 1892 Stephens used funds from the sale of his interest in the Argus to travel through North America and Europe, sending articles on his travels to various Australian periodicals. In 1893, when Stephens was working for London's Daily Chronicle, he was offered the position of sub-editor at the Sydney Bulletin, an offer he took up in 1894.
In 1896 Stephens took over the inside pages of the Bulletin's red covers and initiated the famous "Red Page". On these pages he provided readers access to a wider range of world literature and promoted local literary talent. For ten years Stephens maintained a major influence over Australia's literary culture through his advice to young writers and opinions on the nature of Australian literature. This influence was strengthened through his editorship of the Bulletin's publishing arm where writers such as Henry Lawson and Joseph Furphy saw their work published in book form. Stephens' criticism was often feared, but the quality of his advice was acknowledged by writers such as Furphy, John Shaw Neilson, Hugh McCrae, Mary Gilmore and Miles Franklin. While Stephens is mainly remembered for his time at the Bulletin, he also published in book form his own poetry, criticism, fiction, non-fiction and plays. Throughout his life he published pamphlets on literary, political and social topics, and, in later life, he edited text books and anthologies for Australian schools.
In 1899 Stephens was the Sydney representative for The Australasian Literary Agency "for the especial service of Australian writers" (The Australian Magazine, 18 September, 1899, p.vi). A. W. Jose was the London representative .
Stephens left the Bulletin in 1906 and opened a bookshop called the Bookfellow which took its name from Stephens' short-lived literary magazine of the 1890s. The magazine was resumed at this time, but by 1907, both ventures had failed and Stephens was forced to sell all his stock, even his own books, to pay his creditors. He spent two years in New Zealand trying to retrieve his financial position. The Bookfellow was resurrected on two other occasions, and was sometimes the only literary magazine in Australia, providing important space for many young writers. Stephens also worked as a freelance writer and teacher, but did not reach the level of influence of his earlier career. Nevertheless, when he died in 1933, he was widely remembered for his major contribution to Australian literature .