Dr Brendan Nelson AO is a former Australian politician who served as the federal Leader of the Opposition from 2007 to 2008. He was a member of the House of Representatives from 1996 to 2009, as the Liberal member for the seat of Bradfield in North Sydney.

A medical doctor by profession, he came to public prominence as the Federal President of the Australian Medical Association (1993– 95), and served as a Minister in the third and fourth terms of the Howard Government, serving as Minister for Education, Science and Training (2001–06) and Minister for Defence (2006–2007).

Following the 2007 federal election, at which the Howard Government was defeated, Dr. Nelson was elected leader of the Liberal Party in a contest against former Minister for Environment and Water Resources Malcolm Turnbull, and became the Leader of the Opposition in December 2007. Less than a year later, in a second contest following a spill motion, Dr Nelson lost the leadership of the Opposition and the Liberal Party to Mr. Turnbull.

On his retirement from politics he became Ambassador of Australia to the European
Union, Belgium and Luxembourg as well as Australia’s Special Representative to NATO. In 2012 he resigned as an ambassador and took on the role of Director of the Australian War Memorial.