He was born Frederick Temple Blackwood into "the Ascendancy", Ireland's Anglo-Irish aristocracy, the son of Price Blackwood, 4th Baron Dufferin and Claneboye. On his father's side, Dufferin was descended from Scottish settlers who had moved to County Down in the early 17th century. The Blackwood family became prominent landowners in Ulster over the following two hundred years, and were created baronets in 1763, entering the Peerage of Ireland in 1800 as Baron Dufferin. The family had influence in parliament because they controlled the return for the borough of Killyleagh. Marriages in the Blackwood family were often advantageous to their landowning and high-society ambitions. His mother, Helen Selina Sheridan, was the granddaughter of the playwright Richard Brinsley Sheridan and through her the family became connected to English literary and political circles.