In 1868 Poë married Mary Adelaide, daughter of Sir William Compton Domville, 3rd Bt. They had a son and a daughter. A retired Lieutenant-Colonel, Poë was wounded in the Egyptian Expedition in 1884, and lost a leg in the Nile Expedition of 1884-85. He served also as His Majesty's Lieutenant for Queen's county, High Sheriff of that county in 1891, and of county Tyrone [both in Northern Ireland] in 1893. He was a Governor of the National Gallery of Ireland and was a member of the Irish Land Conference in Dublin (1902), and of the Vice-Regal Commission on Irish Railways (1906-10). Sir William was created a Baronet in July 1912.
Burke, Ashworth P. and Sir Bernard. A Genealogical and Heraldic History of the Peerage and Baronetage. 86th ed. London, 1928: 1857-1858.