Despite his Italian-sounding name, Ignatius Bonomi (1787-1870) was an English architect and surveyor, strongly associated with Durham in north-east England.

He was the son of an architect and draughtsman, Joseph Bonomi (1739-1808), who had worked with Robert and James Adam, while his brother Joseph Bonomi the Younger was a noted artist, sculptor and Egyptologist.

Ignatius's work (he was Surveyor of Bridges for the County of Durham) included one of the first railway bridges in the UK (over the River Skerne , near Darlington), for the Stockton and Darlington Railway, in 1824 (hence he is sometimes referred to as 'the first railway architect').

He was also responsible for a number of church buildings (including commissions at Durham Cathedral). Other historic buildings, in Gothic and neo-classical styles, included Durham Castle, Lambton Castle (continuing the work started by his father), Durham Prison , Elvet Hill House (1820), Burn Hall and Eggleston Hall, all in County Durham.

Slightly further afield, other works included design of Marton House near Appleby-in-Westmoreland , Cumbria (1822), Blagdon Hall (1830) in Stannington near Morpeth, Northumberland, the church of St John the Baptist in Leeming, North Yorkshire (1839) and restoration of St Nicholas House, Richmond, North Yorkshire. For his brother Joseph, he also designed a house, 'The Camels', at Wimbledon in south-west London.

In 1831, Bonomi took on John Loughborough Pearson as an apprentice. In 1842 he entered into a partnership with John Augustus Cory , later Cumberland County Architect (from 1862). The church of St John the Evangelist, Nenthead (1845, the highest church in England) was one of their joint projects.