Hornabrook was born in Adelaide, the oldest son and second child of Charles Atkins Hornabrook JP and his wife Eliza Maria Hornabrook, née Soward,. He was educated at St Peter's College and joined the architectural firm of Woods and McMinn, spending two years in England furthering his education at the Royal Academy architectural schools, during which time he wrote a monograph on the history of stained glass in England, read before the St George's Art Society and as Painted Glass published in The Furniture Gazette Vol. XXIII p.135 London 1885. and was serialized in The Building News. He then worked for two years as catechist under the Rev. R. H. Phillips, incumbent of St John's Church, Taree, New South Wales. In January 1887 he left Australia to study for Holy Orders at Lincoln Theological College, where he gained first class honours in the 1889 examinations. That same year he was ordained by Edward King, Bishop of Lincoln, and returned to Australia, and in November 1889 was sent to the Diocese of Newcastle, New South Wales. In 1892 he returned to Adelaide as curate of St John's Church, serving mostly at St Mary Magdalene's mission church, 26–28 Moore Street, and fostered the formation of other groups, including three Boy Scout troops. He was made a Canon in 1911. In 1918 he succeeded Bishop Wilson as Archdeacon of Adelaide, the first native South Australian to hold that position. ;St Peter's Mission In 1908 St Peter's College followed the lead of similar public schools in England in establishing an outreach mission at St Mary Magdalene Church, Moore Street, city to benefit people in one of the poorer districts of Adelaide, and Hornabrook was appointed missioner. Hornabrook had a considerable influence on the architecture and fitting-out of the mission church, decidedly in the Anglo-Catholic mould. ;Barwell Boys In 1922 Premier Henry Barwell announced the "South Australian Farm Apprenticeship Scheme", when thousands of impoverished and orphaned English boys were brought in to relieve the shortage of farm labourers resulting from WWI casualties. A form of philanthropy, but also described as "more cheap labor", Hornabrook was at the forefront of assisting their settlement in the new country. ;Ritualism Hornabrook was criticised for his promotion of Anglo-Catholic vestments as adopted by the new headmaster of St Peter's College. Hornabrook was accused, along with Canon Wise of turning the college into an institution for turning out High Church priests. He died suddenly and unexpectedly, while still vigorous and active despite his 62 years of age. His remains were interred at the North Road Cemetery.
Family
Rev. Charles Soward Hornabrook married Anna Elizabeth Johanna Newton on 1 July 1891
