Initially a Liberal,[3] he was the Home Rule League MP for Cavan, elected for 1874 and 1880 holding his seat until the constituency was abolished in 1885.
In January, 1878 he was elected to the Statistical and Social Inquiry Society of Ireland.
[4] In contrast to many fellow Home rulers, his opposition to the Irish Coercion Acts was reported as lacklustre.
[5] He was the youngest of the four sons of Thomas Fay (b 1791) of Faybrook, Cootehill, County Cavan.
His brother James-Henry Fay, J.P.,[6] was High Sheriff of Cavan from 23 Feb 1881 until 25 Jan 1882.