Little is known about his early life. He married Mary Ann Harrison on February 17, 1844. A son Oscar L. Fraser worked as an assistant in the Indian Museum at Calcutta around 1888. He worked for fourteen years at the museum of the Zoological Society of London. He worked with the anatomist Richard Owen on studies of the emu and rhea. He participated in the Niger expedition of 1841 as the African Civilization Society's scientist, with Allen and Thomson. He stayed on in Fernando Po and collected. Upon his return he became in charge of Lord Derby's collection at Knowsley Hall. In 1846 he was sent by Lord Derby to collect in north Africa. Ind 1848 he became conservator at Knowsley. He wrote Zoologica Typica, or figures of the new and rare animals and birds in the collection of the Zoological Society of London, a lavishly illustrated large-sized book, published in 1849. In this book he described a large number of new species of birds. In 1850, Fraser was appointed Consul of Quidah, Dahomey (now Benin), West Africa. Around 1857-1859, he collected birds and mammals in Ecuador for Philip Lutley Sclater of the Zoological Society of London, and the year after in California. Upon his return to London, he opened a shop in Regent Street, London, selling exotic birds. The last years of his life he spent in America.
Fraser wrote a Catalogue of the Knowsley Collections (1850) and described several species include the Derbyan Parakeet Psittacula derbiana after his employer. A number of species have been named in his honour, including Fraser's Eagle-Owl, Bubo poensis, Fraser's Warbler, Basileuterus fraseri and Fraser's Musk Shrew, Crocidura poensis.
- Darwin, Charles; Frederick Burkhardt; Sydney Smith (1985). The Correspondence of Charles Darwin: Volume 5. Cambridge University Press. p. 489. ISBN 0-521-25591-0.
- Fisher, Clemency Thorne (2004). Oxford Dictionary of National Biography. Oxford University Press. doi:10.1093/ref:odnb/10118.
- Beolens, Watkins & Grayson (2009). The Eponym Dictionary of Mammals. Johns Hopkins University Press. ISBN 0-8018-9304-6.
- Basileuterus fraseri on Avibase
- Günther, Albert C. L. G. (1906). The history of the collections contained in the Natural History Departments of the British Museum. Volume 2. London: British Museum. p. 33.