Born in Glasgow, Frazer attended school at Springfield Academy and Larchfield Academy in Helensburgh. He studied at the University of Glasgow and Trinity College, Cambridge, where he graduated with honors in Classics (his dissertation would be published years later as The Growth of Plato's Ideal Theory) and remained a Classics Fellow all his life. He went on from Trinity to study law at the Middle Temple and yet never practised. He was four times elected to Trinity's Title Alpha Fellowship, and was associated with the college for most of his life, except for a year, 1907—1908, spent at the University of Liverpool. He was knighted in 1914, and a public lectureship in social anthropology at the universities of Cambridge, Oxford, Glasgow and Liverpool was established in his honour in 1921. He was, if not blind, then severely visually impaired from 1930 on. He and his wife, Lily, died within a few hours of each other. They are buried at the Ascension Parish Burial Ground in Cambridge, England.

The study of myth and religion became his areas of expertise. Except for visits to Italy and Greece, Frazer was not widely traveled. His prime sources of data were ancient histories and questionnaires mailed to missionaries and Imperial officials all over the globe. Frazer's interest in social anthropology was aroused by reading E. B. Tylor's Primitive Culture (1871) and encouraged by his friend, the biblical scholar William Robertson Smith, who was linking the Old Testament with early Hebrew folklore.

Frazer was far from being the first to study religions dispassionately, as a cultural phenomenon rather than from within theology. He was, though, the first to detail the relations between myths and rituals. His theories of totemism were superseded by Claude Lévi-Strauss and his vision of the annual sacrifice of the Year King has not been borne out by field studies. His generation's choice of Darwinian evolution as a social paradigm, interpreted by Frazer as three rising stages of human progress...magic giving rise to religion, then culminating in science...has not proved valid. Yet The Golden Bough, his study of ancient cults, rites, and myths, including their parallels with early Christianity, arguably his greatest work, is still rifled by modern mythographers for its detailed information. The work's influence spilled well over the conventional bounds of academia, however; the symbolic cycle of life, death and rebirth which Frazer divined behind myths of all pedigrees captivated a whole generation of artists and poets. Perhaps the most notable product of this fascination is T. S. Eliot's poem The Waste Land (1922). More recently it was an influence on the ending of Francis Ford Coppola's film Apocalypse Now (a copy of The Golden Bough figures in one of the final shots).

The first edition, in two volumes, was published in 1890. The third edition was finished in 1915 and ran to twelve volumes, with a supplemental thirteenth volume added in 1936. He also published a single volume abridgement, largely compiled by his wife Lady Frazer, in 1922, with some controversial material removed from the text.

Jane Ellen Harrison, a respected historian of Greek religion and a Fellow of Newnham College, Cambridge, gave Frazer's immensely popular work academic credibility, and it has retained the reputation of a middle-brow classic.

Frazer's pioneering work"For those who see Frazer's work as the start of anthropological study in its modern sense, the site and the cult of Nemi must hold a particular place: This colourful but minor backwater of Roman religion marks the source of the discipline of Social Anthropology", remarks Mary Beard, in noting the critical reassment of Frazer's work following Edmund Leach, "Frazer, Leach, and Virgil: The Popularity (and Unpopularity) of the Golden Bough" Comparative Studies in Society and History 34.2 (April 1992:203-224), p. 204. has come under criticism by more recent scholars, following a series of critical, even vituperative articles by Edmund Leach, one of which was selected as the lead article in Anthropology Today, vol. 1 (1985); in part Frazer's Golden Bough was criticised for the breadth of comparisons drawn from widely separated cultures, but the criticism is often based on the abridged edition, which omits the supportive archaeological details. In a positive review of a work narrowly focusing on the cultus in the Hittite city of Nerik, J. D. Hawkins remarked approvingly in 1973, "The whole work is very methodical and sticks closely to the fully quoted documentary evidence in a way that would have been unfamiliar to the late Sir James Frazer."Frazer's six volume commentary on the Greek traveler Pausanias' description of Greece in the mid 2nd c. AD remains one of his most important works although archaeological excavations have added enormously to our knowledge of Greece since his time. There is still much of value in his detailed historical and topographical discussions of different sites and his eyewitness accounts of Greece at the end of the 19th century.