Wilde's mother is American, and her father was born in London to a British family and raised in Ireland. Her ancestry includes English, Irish, Scottish, German, and Manx.
Olivia Wilde was born on March 10, 1984, in New York City. Her parents are Leslie Cockburn (née Leslie Corkill Redlich) and Andrew Cockburn. Her mother is American-born and her father was born in London, England to an upper-class British family; he also later became a citizen of Ireland. Wilde is the middle child, having an older sister, Chloe Cockburn, and, a younger brother, Charlie Cockburn. She was raised in Georgetown, Washington, DC, and spent her summers in Ardmore, County Waterford, Ireland.
Wilde's paternal Scottish ancestors were upper-class and lived in many locations at the height of the British Empire, including Peking (where her paternal grandfather was born), Calcutta, Bombay, Cairo, and Tasmania. A great-great-grandfather, Henry Arthur Blake, was governor of Hong Kong. Her other paternal ancestors include abolitionist and Anglican minister James Ramsay; politician George Arbuthnot; lawyer, judge, and literary figure Henry Cockburn, Lord Cockburn; Lord Provost of Edinburgh Sir William Arbuthnot; and Sir Thomas Osborne. Wilde's family is also related to Sir George Cockburn, 10th Baronet, who was responsible for burning down Washington, DC in the War of 1812. Olivia is also a descendant of Margaret Tudor, sister of Henry VIII, through Margaret's son, James V, King of Scotland.