Born at Littlebourne, Kent, England, on 26 July 1852 and died at Sydney, N.S.W., on 19 September 1924.
For reasons of health he migrated to New South Wales in 1883 and the next year obtained a position on the staff of the Sydney Technological Museum. He began to study scientific subjects, in particular chemistry, and in 1891 was appointed a laboratory assistant at the museum and contributed his first paper to the Linnean Society of New South Wales. The year 1895 saw him appointed mineralogist to the museum and, in conjunction with J. H. Maiden, he read his first paper on organic chemistry to the Royal Society of New South Wales. From 1891 to 1911 he lectured on organic chemistry at Sydney Technical College. Smith was appointed assistant curator and economic chemist at the museum in 1899 and held the positions until his retirement in 1921.
His long and notable association with eucalypts and other forest trees of Australia can be said to have begun in 1896 when he commenced a long collaboration with R. T. Baker. The first work was investigating essential oils in eucalypts, with Baker working on the botanical side and Smith on the chemical side, the published result being A Research on the Eucalypts, especially in regard to their Essential Oils (first published 1902, revised 1920). Another work by the same two authors was A Research on the Pines of Australia (1910). Another notable joint publication was Wood Fibres of Some Australian Timbers (1924).
From about 1914 Smith had been informally associated with the organic chemistry department of the University of Sydney and he continued to work there after he retired from the museum. He was a member of the Royal Society of New South Wales and its president in 1913; president of the Australian Chemical Institute in 1922-23 and of the Chemistry Section of the Australasian Association for the Advancement of Science at the meeting held in Wellington, N.Z., in 1923. Smith was the author of more than 100 papers, 62 of which appeared in J. Roy. Soc. N.S. W and others in J. Proc. Aust. Chem. Inst. His work on the essential oils of the Australian flora achieved worldwide reputation.
He is honoured in the name Eucalyptus smithii R. T. Bak. (1899)