Peter Benjamin Mandelson, Baron Mandelson, is a British Labour Party politician who served as First Secretary of State from 2009 to 2010. He was President of the Board of Trade in 1998 and from 2008 to 2010. He is the president of international think tank Policy Network, honorary president of the Great Britain–China Centre, and chairman of strategic advisory firm Global Counsel. Mandelson is often referred to as a Blairite.

First Secretary of State is an office that is sometimes held by a minister of the Crown in the Government of the United Kingdom. The office indicates seniority, including over all other secretaries of state. The office is not always in use, so there have sometimes been extended gaps between successive holders.