Isaac Butt, an Irish lawyer, politician, and author, born at Glenfin, county Donegal, Ireland, in 1813. He was educated at Trinity college, Dublin, where he obtained a scholarship in 1832, graduated in 1835, was appointed Whately professor of political economy in 1836, and called to the Irish bar in 1840. He was elected a member of the corporation of Dublin, and in 1843 opposed O'Connell's agitation for a repeal of the union. In the Irish state trials of 1848 he acted as counsel for Smith O'Brien and others, and in 1865 for several of the Fenian prisoners. In 1850 he was an unsuccessful candidate for parliament for Mayo, but was elected for Harwich, and in 1852 for Youghal, which he represented till 1865, and in 1871 was returned for Limerick, in the interest of the "national and home rule" movement, of which he was the originator. He is a magistrate for the county of Cork. He was one of the projectors of the "Dublin University Magazine," of which he was for some time editor, and to which he contributed " Chapters of College Romance," republished in a separate form.

In 1860 he published a "History of the Kingdom of Italy," and in 1870 a "Practical Treatise on the New Law of Compensation to Tenants in Ireland".