R. D. FitzGerald was born in Sydney and educated at Sydney Grammar School. FitzGerald attended the University of Sydney, but discontinued his studies to pursue a career as a surveyor. This career took him to Fiji for most of the 1930s and saw him appointed to several positions in the Commonwealth Department of the Interior before his retirement in 1965.
In the 1920s, FitzGerald published a number of poems in periodicals such as Hermes, The Bulletin, Triad and Vision. Several poems also appeared in Poetry in Australia, 1923. Between 1927, when his first, privately distributed volume appeared, and 1977, when his last collection appeared, FitzGerald published more than a dozen collections of poetry. Ranging from short, metaphysical poems to long dramatic narratives, FitzGerald displayed a quality and diversity that attracted many awards and honours, including three Grace Leven Prizes, the Robert Frost Medallion (1974) and an OBE. In addition to his poetry, his reviews and commentary appeared regularly in various periodicals. In 1959 and 1961 he gave a series of Commonwealth Literary Fund lectures at universities in Melbourne and Brisbane which was later published as The Elements of Poetry (1963). His university experience was further extended as visiting lecturer in English at the University of Texas in 1963.
Despite an outstanding reputation in the 1950s and 1960s, critical opinion on the value of FitzGerald's poetry has remained divided and, since the mid-1970s, his poetry has stimulated little discussion in academic journals. FitzGerald's use of poetry to explore complex philosophical ideas sometimes sees him compared with Christopher Brennan and deemed inaccessible to many readers. Furthermore some modern critics, such as James McAuley, questioned the quality of some of FitzGerald's collections. But such opinions contrast with the high praise of other critics such as T. Inglis Moore, A. Grove Day and Julian Croft who appreciate the consistent technical brilliance and experimentation that delivers the intellectual messages of FitzGerald's poetry.
In 1987, the year of FitzGerald's death, Julian Croft published a selection of prose and poetry that attempted to revive FitzGerald's reputation. Since that time, little substantial criticism has appeared, but FitzGerald remains a major figure in the history of Australian poetry.
FitzGerald was the nephew of John le Gay Brereton and was also related to Mary Gilmore.