November 2, 1842, Taunton, Somerset, England.
March 11, 1908, Stratton-on-the-Fosse, Somerset, England.
Olinthus was the son of James Barnicott, a painter, and Hephzibah Warren, and husband of Mary Elizabeth Ann Slater. He was educated at St John’s College, Cambridge (BA & LLB 1882, LLM 1885, LLD 1897), ordained an Anglican deacon in 1886, and ordained a priest at Winchester in 1887.
Barnicott served as clerk of St. Mark, Woolston, Hampshire (1886–89); clerk of Holy Trinity, Ryde, Isle of Wight (1890–91); clerk of Eling (1892–95); priest in the diocese of Chichester (1897–1902); chaplain to the Cottismore School in Brighton (1898–1905); clerk of Preston in Brightaon (1902–05); and rector of Stratton-on-the-Fosse (1905–08).