Arthur Edward Guinness, Baron Ardilaun (November 1, 1840) - (January 20, 1915) was an Irish businessman, politician, and philanthropist. Born at St Anne's, Clontarf, near Dublin, he was the eldest son of Sir Benjamin Guinness, 1st Baronet, and elder brother of Edward Cecil Guinness, 1st Earl of Iveagh. He was educated at Eton and Trinity College Dublin, and in 1868 succeeded his father as second Baronet. That same year he was elected Conservative Member of Parliament for the City of Dublin, a seat he held for only a year but which he won again in 1874.
After withdrawing from the Guinness company in 1876, Sir Arthur Guinness was in 1880 created Baron Ardilaun, of Ashford in the County of Galway. He was, like the rest of his family, a generous philanthropist, devoting himself to a number of public causes, including the restoration of Marsh's Library in Dublin and the extension of the city's Coombe Hospital. He also presented the capital with the public park of St Stephen's Green.
President of the Royal Dublin Society (1892-1913), Lord Ardilaun died childless in 1915 at his home at St Anne's, Clontarf, and was buried at All Saints, Rahemy, County Dublin. His barony became extinct at his death, but the baronetcy devolved upon his nephew.
