Sir David Geoffrey Manning, GCMG, KCVO (born 5 December 1949) is a former British diplomat, who was the British Ambassador to the United States from 2003 to 2007. He authored the so-called "Manning Memo" summarising the details of a January 2003 meeting between American president George W. Bush and British prime minister Tony Blair during the run-up to the invasion of Iraq. He has since been appointed to the Household of TRH The Duke and Duchess of Cambridge and Prince Harry.