Katharine Teresa Gun (née Harwood; born 1974) is a British linguist who worked as a translator for the Government Communications Headquarters (GCHQ). In 2003, she leaked top-secret information to a friend who passed it to The Observer. The information concerned a request from the United States for compromising intelligence on diplomats from member states of the 2003 United Nations Security Council, who were due to vote on a second UN resolution on the prospective 2003 invasion of Iraq.