Agnes Georgiana Elizabeth Duff, Countess Fife (née Hay; 12 May 1829 – 18 December 1869) was a Scottish aristocrat.
[1] On 16 March 1846, Hay was married to James Duff, son of General Hon.
Sir Alexander Duff and Anne Stein, at the British Embassy in Paris, France.
[2] Duff later inherited the earldom of Fife upon the death of his uncle in 1857.
The marriage had issue: Agnes died at the age of 40.