Moore was born in South London on 4 November 1873. His eldest brother was Thomas Sturge Moore, a poet, writer and engraver.
In 1892, he was educated at Dulwich College and then attended Trinity College Cambridge to study classics for moral sciences. He became a Fellow of Trinity in 1898, and went on to hold the University of Cambridge chair of mental philosophy and logic, from 1925 to 1939.
Moore is best known today for his defence of ethical non-naturalism, his emphasis on common sense in philosophical method, and the paradox that bears his name. He was admired by and influential among other philosophers, and also by the Bloomsbury Group, but is (unlike his colleague Russell) mostly unknown today outside of academic philosophy. Moore's essays are known for their clear, circumspect writing style, and for his methodical and patient approach to philosophical problems. He was critical of modern philosophy for its lack of progress, which he believed was in stark contrast to the dramatic advances in the natural sciences since the Renaissance. Among Moore's most famous works are his book Principia Ethica, and his essays, "The Refutation of Idealism", "A Defence of Common Sense", and "A Proof of the External World".
He was president of the Aristotelian Society from 1918-19.
Paul Levy wrote in Moore: G. E. Moore and the Cambridge Apostles (1979) that Moore was an important member of the secretive Cambridge Apostles.
G. E. Moore died on 24 October 1958; he was cremated at Cambridge Crematorium on 28 October 1958 and his ashes interred at the Parish of the Ascension Burial Ground in Cambridge, England; his wife, Dorothy Ely (1892-1977) was buried there. Together they had two sons, the poet Nicholas Moore and the composer Timothy Moore.