David William Donald Cameron (born 9 October 1966) is the leader of the Conservative Party and Leader of the Opposition in the United Kingdom. He has occupied both positions since December 2005.

He read Philosophy, Politics and Economics at Oxford, gaining a first class honours degree. He then joined the Conservative Research Department and became Special Adviser to Norman Lamont, and then to Michael Howard. He was Director of Corporate Affairs at Carlton Communications for seven years.

A first candidacy for Parliament at Stafford in 1997 ended in defeat but Cameron was elected in 2001 as Member of Parliament for the Oxfordshire constituency of Witney. Promoted to the Opposition front bench two years after entering Parliament, he rose rapidly to be head of policy co-ordination during the 2005 general election campaign.