This article discusses leadership in urban governance by examining the Mayor of London. It uses a conceptual framework of four elements: the external environment to local leadership; the institutional arrangements in which leaders operate; the local environment; and the personal characteristics of leaders. It is argued that the Mayor of London is 'strong' within the Greater London Authority, but 'weak' in formal terms in the governance of London. In order to be effective in London governance, the Mayor needs to facilitate the co-operation of others in order to wield power. The area of negotiation of the leadership of the Mayor of London is broad and takes place between the Mayor and the organisations which form the governance of London.