Kathryn "Kat" Jane Fletcher (born 20 December 1979) is a British Labour Party politician. In May 2016, she was sworn in as the Mayor of Islington, having served as a councillor of the borough's St George's Ward since 2013. She was previously president of the National Union of Students, between 2004 and 2006, the first to be elected from a political slate to the left of Labour Students.