Seymour, Michael Hobart (1800–74), clergyman and controversialist, was born 29 September 1800, sixth son of the Rev. John Crossley Seymour (d. May 1831), vicar of Caherelly, Co. Limerick, and his wife, Catherine, eldest daughter of the Rev. Edward Wight, rector of Meelick, Co. Limerick. His family claimed descent from Sir Henry Seymour, brother of Jane Seymour, third wife of Henry VIII. His elder brother Aaron Crossley Hobart Seymour (1789–1870) was a noted writer on religious subjects.
Educated by private tutor, he entered TCD 7 July 1817 and graduated BA (1823) and MA (1832). He decided on following a career as a Church of Ireland clergyman and took holy orders, being ordained deacon (1823) and priest (1824). He held several curacies in Ireland, and became a prominent member of the Irish Protestant Association, acting as its secretary while also giving public lectures on the dangers of Roman catholicism. In many ways his lecturing tours cast a shadow over the rest of his clerical career. While his father had been popular among both catholics and protestants in Co. Limerick, Michael Seymour was soon despised by much of the local population.
In 1834 Seymour moved to England, where he gave a series of lectures in London at St George the Martyr, Southwark, and St Anne's, Blackfriars, while also acting as the travelling secretary of the Reformation Society. He was incorporated MA at the University of Oxford in June 1836 and was later awarded a further honorary degree, comitatis causa, by the university (1865). Much of the rest of his life was devoted to writing books attacking the Roman catholic church. His most notable works were A pilgrimage to Rome (1848), Mornings among the Jesuits at Rome (1849), Certainty unattainable in the Romish church (1851), and Evenings with the Romanists (1854; New York and Philadelphia, 1855). Most of these ran to several editions, and Evenings with the Romanists was later translated into Spanish for circulation in Mexico. There was little that was original in his arguments, and his works mostly fed the appetites of those involved in anti-catholic associations.
He also wrote frequent letters on religious matters to the daily broadsheets and published some of his lectures in pamphlet form. One of these, On nunneries (1852), painted a dreadful picture of the lives of those confined in convents. This was a topical issue, and the numerous stories of young women being detained against their will in convents resulted in the Bill to Facilitate the Recovery of Personal Liberty in Certain Cases (1853) (which was never enacted). Cardinal Wiseman later replied in a publication of his own. Seymour's many other publications include a revised edition of Foxe's Acts and monuments of the church (1838) and a pamphlet entitled My experience in the Church of Ireland (1868). He died 19 June 1874 at Marlborough Buildings, Bath, and was buried in Locksbrook cemetery.
He married (1844) Maria, Baroness Brownmill, of Bath, only daughter of Gen. Thomas of the East India Company, and widow of Baron Brownmill, who had been physician to Louis XVIII of France. They had no children.