Boyle’s father had sat in the Irish Parliament for Clonakilty, 1794-7, and county Cork, 1797-1800, which he continued to represent from the Union until 1807, when he returned himself for the family boroughs of Bandon Bridge and Youghal shortly before succeeding to the earldom in May 1807. In 1817, in an attempt to shore up the family’s declining influence in county Cork, he abandoned the Liverpool government and allied himself with the 3rd earl of Kingston, then a Whig, with whose family he continued to act throughout this period. In November 1829 it was suggested to Shannon that Boyle, whose elder brother had died an infant in 1803, might offer for a vacancy for Cork expected early in 1830, ‘for although his lordship will not be of age to take his seat till ... May ... yet it does not prevent his being elected five or six weeks before’.
In his only known speech, 11 Nov. 1830, Boyle welcomed the Wellington ministry’s intended review of the ‘exceedingly unpopular’ Irish Subletting Act and called for a ‘tax in support of the Irish poor’ to be imposed on absentee landlords, which would provide ‘protection to the ratepayers of England’ and ‘improve the condition and character of the Irish peasantry’. He had been listed by ministers as one of their ‘friends’, but was absent from the crucial division on the civil list, 15 Nov. He presented four constituency petitions against slavery, 15 Dec. 1830. He voted for the second reading of the Grey ministry’s reform bill, 22 Mar., but was absent from the division on Gascoyne’s wrecking amendment, 19 Apr. 1831. At the ensuing general election he offered again, promising to support ‘such a fair constitutional reform as will suit the times in which we live and ... uphold the rights of the crown, the aristocracy, and the people’. Pressed on the hustings to clarify whether he would support the ‘whole bill’, he promised that he would ‘stand by it to the last’, adding that he had been ‘confined by indisposition when the debate on Gascoyne’s motion took place, or the ministry should have had his support’. He was again returned unopposed.
At the 1832 dissolution Boyle retired from county Cork. He succeeded his father in the peerage in 1842 and sat in the Lords as a Conservative. In 1865 he repeatedly pestered the Irish viceroy Lord Wodehouse about the ‘dangers of a rising’ by the Fenians in county Cork, in anticipation of which he had removed all his ‘plate and portable things of value to London’.
