Born in Launceston, Tasmania, Oliver emigrated with his family to Tauranga in 1896. Having already developed an interest in nature during his childhood, he systematically recorded natural observations throughout much of his life, joining other naturalists on an expedition to the Kermadec Islands as early as 1908.
In 1910 he became a member of the Royal Australasian Ornithologists Union (RAOU) for which body he served as Branch Secretary for New Zealand from 1914 to his death in 1957, an extraordinary period of office of 43 years. During this period he also served as RAOU Vice-President 1942-1943, and as President 1943-1944.
Oliver was appointed Director of the Dominion Museum in 1928 1, and in 1930, he published the seminal guide New Zealand Birds, which was updated and expanded in 1955. The guide contained many colour plates by Lily Attey Daff, although she was not credited with the work. Oliver retired from the position of Director in 1947. Oliver was active in numerous scientific societies, and was a prolific contributor to New Zealand scientific literature over a long career e.g. he was Government representative on the Council of the Royal Society of New Zealand for many years, its president from 1952 to 1954, and editor of its Transactions from 1948 to 1954.
Oliver described several species new to science, including:
- Coan EV, Kabat AR, Petit RE (15 February 2009). 2,400 years of malacology, 6th edition. American Malacological Society. 830 pp. & 32 pp. [Annex of Collations].
- "An Artistic Worker: Death of Miss L. A. Daff". paperspast.natlib.govt.nz. Retrieved 11 March 2019.
- Beolens B, Watkins M, Grayson M (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN 978-1-4214-0135-5. ("Oliver, W.R.B.", p. 194).
- "Official jubilee medals". The Evening Post. CXIX (105). 6 May 1935. p. 4. Retrieved 17 November 2013.
- IPNI. W.R.B.Oliv.
- Dawson EW (1958). "Walter Reginald Brook Oliver (1883-1957)". Proceedings of the Malacological Society of London 33 (1): 1.
- Dell RK (1998). "Oliver, Walter Reginald Brook 1883-1957". Dictionary of New Zealand Biography 4: 389-390. HTM.
- WRB Oliver from Encyclopedia of New Zealand (1966)
- some (not all) articles by Walter Oliver in Transactions and Proceedings of the Royal Society of New Zealand