Guinness is the third son of Arthur Guinness II (1768–1855), and his wife Anne Lee, and a grandson of the first Arthur (1725–1803), who had bought the St. James’s Gate Brewery in 1759. He joins his father in the business in his late teens, without attending university, and from 1839 he takes sole control within the family. From 1855, when his father dies, he has become the richest man in Ireland, having built up a huge export trade and by continually enlarging his brewery.
In 1851 Guinness is elected the first Lord Mayor of Dublin under the reformed corporation. In 1863 he is made an honorary LL.D. (Doctor of Laws) by Trinity College Dublin, and on April 15, 1867 is created a baronet by patent, in addition to which, on May 18, 1867, by royal licence, he has a grant of supporters to his family arms.
Guinness is elected to the House of Commons of the United Kingdom in 1865 as a Conservative Party representative for Dublin City, serving until his death. His party’s leader is Edward Smith-Stanley, 14th Earl of Derby. Previously he had supported the Liberal Party‘s Henry John Temple, 3rd Viscount Palmerston, but in the 1860s the Liberals propose higher taxation on drinks such as beer. Before 1865 the Irish Conservative Party does not entirely support British conservative policy, but does so after the Irish Church Act 1869. The government’s most notable reform is the Reform Act 1867 that expands the franchise.
From 1860 to 1865, Guinness undertakes at his own expense, and without hiring an architect, the restoration of the city’s St. Patrick’s Cathedral, an enterprise that costs him over £150,000. In 1865 the building is restored to the dean and chapter, and reopens for services on February 24. The citizens of Dublin and the dean and chapter of St. Patrick’s present him with addresses on December 31, 1865, expressive of their gratitude for what he has done for the city. The addresses are in two volumes, which are afterwards exhibited at the Paris Exhibition.
In recognition of his generosity, Guinness is made a baronet in 1867. He is one of the ecclesiastical commissioners for Ireland, a governor of Simpson’s Hospital, and vice-chairman of the Dublin Exhibition Palace. He dies the following year, on May 19, 1868, at his Park Lane home in London. At the time of his death he is engaged in the restoration of Marsh’s Library, a building which adjoins St. Patrick’s Cathedral. The restoration is completed by his son Arthur.
Guinness is buried in Mount Jerome Cemetery, Dublin, in the family vault, on May 27, 1868. His personalty is sworn under £1,100,000 on August 8, 1868. A bronze statue of him by John Henry Foley is erected by the Cathedral Chapter in St. Patrick’s churchyard, on the south side of the cathedral, in September 1875, which is restored in 2006.