George Augustus Moore was born on February 24, 1852 to George Henry Moore and Mary Blake Moore of Moore Hall, County Mayo, Ireland. As a boy, he received the private tutoring appropriate to the son of a horse-breeding gentleman and radical Member of Parliament, and in 1861 was sent by his parents to Oscott, a Jesuit school, where, as he noted in Confessions of a Young Man (1888), "it pleased me to read 'Queen Mab' and 'Cain' amid the priests and ignorance of a hateful Roman Catholic college." Moore's father eventually removed him from Oscott at the school's suggestion.
In 1868 George Henry Moore was returned to Parliament after being unseated in 1857, and Moore's family moved to London. In 1870, when Moore was 18, his father died while on business in Ireland, and ownership of the family estate passed into Moore's hands, providing him with a yearly income of between 500 and 4000 pounds per year upon reaching majority. This allowed him, for the rest of his life, to pursue his wide-ranging artistic, literary and philosophical interests.
In 1873, Moore left London for Paris, where he intended to study painting. After enrolling in several studios, first at the Ecole des Beaux Arts and then in several private studios, and making some efforts to master the basics, Moore gave up the notion of becoming a painter, and gave himself over to Parisian cafe society and the conversation of artists and painters. "The creatures whom I met, " he wrote in Confessions of a Young Man (1888), "in the ways and byways of Parisian life, whose gestures and attitudes I devoured with my eyes, and whose souls I hungered to know, awoke in me an intense irresponsible curiosity..."
The first period of Moore's artistic life ended with the death of his mother in 1895, and the publication of his novel Evelyn Innes (1898). From his mother's dead until the Irish playwright Edward Martyn (who was Moore's cousin) began to canjole Moore to join the emerging Irish Renaissance movement in 1900, Moore is very quiet, artistically: he spent that time, as he describes in Hail and Farewell, living in London, reading and writing, working on a few plays, and spending evenings with Martyn, Arthur Symons (who was at the time finishing his masterpiece The Symbolist Movement In Literature (1899), and W.B. Yeats.
What marks this period most clearly is Moore's focus, in Avowals (1919), Conversations in Ebury Street (1924) on establishing himself as a critic, and his canon-making activities: the revision of many of his early works, the attachment of prefaces and other interpretative devices to his novels, and in the creation of the several limited and collected editions of his work -- privately printed in expensive formats, signed and numbered -- that occupied Moore from the early 1920s until his death in 1933.
On his death, Moore's body was cremated and his ashes buried on Castle Island in Lough Carra within sight of Moore Hall.