Grimshaw, Thomas Wrigley (1839–1900), surgeon and medical statistician, was born 16 November 1839 at Whitehouse, near Belfast, Co. Antrim, the son of Wrigley Grimshaw (d. 1878), FRCS, MRIA, dental surgeon at Dr Steevens' Hospital, Dublin (1858–63), and his wife Alicia Grimshaw (they were cousins). The Grimshaws were descended from Lancashire cotton merchants who moved to Greencastle, Co. Antrim, in the eighteenth century and founded a calico-printing business. Thomas was educated at Bryce's Academy, Newry, the Carrickfergus School, at the Academic Institute in Harcourt St., Dublin, and Dr Hare's school in Stephen's Green, Dublin. In November 1856 he entered TCD, where he was a moderator in experimental and natural science and also a Briggs exhibitioner. He graduated BA (1860) and M. Chir. and MB (1861), and was admitted a licentiate of the RCSI in 1862. Further surgical training followed in Sir Patrick Dun's Hospital and Dr Steevens' Hospital, where he was appointed professor of botany (1862–5). In 1865 he was appointed professor of materia medica at Dr Steevens' hospital (1865–78). He graduated MD from TCD in 1867, and was admitted licentiate (1867) and fellow (1869) of the RCPI.
Grimshaw worked as a consulting physician at the Cork Street Fever Hospital, the Coombe Lying-In Hospital, and the Dublin Orthopaedic Hospital, while maintaining his connection with Dr Steevens, where he was appointed physician for outpatients (1869) and junior physician (1870). In 1873 he was awarded a diploma in state medicine by TCD and acquitted himself so well in his viva voce examination that the college granted him an honorary MA the following year. Elected professor of medicine at Dr Steevens’ hospital in 1878, he made a study of nursing practices at the hospital, and his recommendation that a nursing school be established was accepted by the board.
Throughout his career, Grimshaw had a strong interest in public health issues and was a recognised authority on medical statistics. He published many medical articles, mostly in the Dublin Journal of Medical Science. These included ‘On the relation between the distribution of cholera in Dublin during the epidemic of 1866 and the geological structure of the Dublin district’ (vol. lxv, Apr. 1878) and ‘Observations on the relative prevalence of disease and death-rates in town and country districts in Ireland’ (vol. lxxix, May 1885). Appointed registrar-general of Ireland (1879), he resigned his professorship at Dr Steevens’, but became a consulting physician to the hospital in 1880 and was elected to the board of governors in 1881. As registrar, he made improvements in the method of compiling government reports, notably in the modified layout of the 1881 Irish census. He also made a special study of patterns of migration and published pioneering reports on the subject; many of his findings have been disputed by modern economic historians. He served as president of the Statistical Society of Ireland (1888–90) and president of the RCPI (1895–6), and was awarded a CB for his services as registrar in June 1897. He died 23 January 1900 at his home, Priorsland, Carrickmines, Co. Dublin.
In 1865 he married Sarah Elizabeth Thomas, daughter of Rev. T. F. Thomas of Newport, Isle of Wight. They had nine sons and three daughters. One of his sons was Major Cecil Thomas Wrigley Grimshaw (1875–1915), CB, DSO, of the Royal Dublin Fusiliers, who served with distinction in the Boer war and was killed in action at Gallipoli.