Joanne McCartney is a British barrister and Labour Party and Co-operative Party politician. Since 2004, she has served as a member of the London Assembly, representing Enfield & Haringey. Following the election of Sadiq Khan as Mayor of London in 2016, McCartney has served as Statutory Deputy Mayor of London. Prior to her career in politics, McCartney worked as a barrister specialising in employment law. She also worked as an adjudicator for the Housing Ombudsman dealing with disputes between landlords and tenants.