Sherrard, Thomas (c.1750–1837), surveyor and planner, was born to parents whose names are not known, but he was related to a William and David Sherrard, merchants in Dublin, and possibly to Sherrards in Drogheda, Co. Louth. The family name is commoner in the north of Ireland. On 27 February 1766 he enrolled in the Dublin Society's school of figure drawing, and on 17 March 1768 joined the school of ornamental drawing. He was apprenticed to the famous surveyor and mapmaker Peter Bernard Scalé; he set up on his own account in March 1773, but the following year was made a partner in Scalé's company. In 1777 he and another partner, John Brownrigg (qv), left Scalé to set up their own firm, Sherrard & Brownrigg, which continued to produce estate surveys in the French style developed by Scalé and John Rocque (qv). A year later Sherrard was on his own again. He surveyed estates all over the country, and produced elegant maps of places such as the Phoenix Park, Dublin (1773; revised in 1811), and of Athlone (1784). In 1787–8 he produced maps of proposed road realignments and street widenings in and around Naas, Co. Kildare. He was increasingly employed to make surveys and maps for the wide streets commissioners as they planned new streets in Dublin.
In March 1789 he became the first salaried official of the commission; he was described as clerk or secretary, as well as surveyor, and in addition to administrative tasks, carried out a great deal of work on the ground. His responsibilities included surveying and mapmaking, laying out building plots, ascertaining levels, supervising work, and valuing new properties. In the first month in his new post, he produced elevations for the new buildings in Sackville St. (later O'Connell St.), the capital's most important and impressive thoroughfare. The work of the wide streets commissioners radically altered the layout and appearance of the centre of Dublin; their influence even on privately developed parts of the city was considerable, and much of the credit for the elegant consistency of the city's eighteenth-century development must be given to Sherrard, who was himself a property developer; Sherrard St. in the north of the city seems to have been his own project. His achievements also include the production of one of the most ambitious maps of the city, completed between 1791 and 1797, at the unprecedented scale of one inch to eighty feet (1:960). This seems to have been used as the basis for a valuation of city properties, associated with his name, which was initiated by an act of 1824. It cost £1,200 to produce, but was never published (and was lost during the late nineteenth century). As well as carrying out so much of the work of the wide streets commission, Sherrard maintained his private practice, working for over twenty years in association with Richard Brassington, his former apprentice; as well as working as surveyors, the company also undertook some of the functions of estate agents. A son, David Henry Sherrard, succeeded him as secretary to the wide streets commissioners in 1833, though by then the glory days of Dublin's redevelopment and expansion were long gone. Sherrard died 11 March 1837, probably at his country residence, Coolock Lodge outside Dublin.
He married (June 1773) Mary Rathwell or Rothwell from Drogheda. As well as at least one son, they had at least five daughters, some of whom died young. His daughter Maria married James Corry (qv) (d. 1837?), clerk of the linen board.