Prior to her career in politics, Joanne 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.

[1][2] McCartney was elected councillor in the London Borough of Enfield in 1998, representing Edmonton and then Palmers Green.

[8] As Deputy Mayor, McCartney has led work on the Mayor of London's universal free school meals programme [9] and on the Young Londoners fund and worked to create "Early Years Hubs" for disadvantaged children.

[10] As an Assembly Member, she has campaigned on rail devolution[11] upgrades to the Piccadilly Line[12] and child poverty.