Robert Harley, 1st Earl of Oxford and Earl Mortimer (5 December 1661 – 21 May 1724), was a British politician and statesman of the late Stuart and early Georgian periods. He began his career as a Whig, before defecting to a new Tory Ministry. He was raised to the peerage as an earl in 1711. Between 1711 and 1714 he served as Lord High Treasurer, effectively Queen Anne's chief minister. He has been called a Prime Minister, though it is generally accepted that the position was first held by Sir Robert Walpole in 1721.
Harley's government agreed to the Treaty of Utrecht with France in 1713, bringing an end to twelve years of British involvement in the War of the Spanish Succession. In 1714 he fell from favour following the accession of the first monarch of the House of Hanover, George I and was for a time imprisoned in the Tower of London by his political enemies.
He was also a noted literary figure and served as a patron of both the October Club and the Scriblerus Club. Harley Street is sometimes said to be named after him, although it was his son Edward Harley who actually developed the area.