The 1998 Greater London Authority referendum was held in Greater London on 7 May 1998, asking whether there was support for creating a Greater London Authority, composed of a directly elected Mayor of London and a London Assembly to scrutinise the Mayor's actions.

The question that appeared on ballot papers in the referendum before the electorate was: Are you in favour of the Government's proposals for a Greater London Authority, made up of an elected mayor and a separately elected assembly?

The lowest support figures were 60.5% in Havering and 57.1% in Bromley; the greatest were 83.8% in Haringey and 81.8% in Lambeth.

The income level of boroughs was an even greater factor affecting the outcome.

Sadiq Khan (L) Statutory Deputy Mayor Joanne McCartney (L/Co) London Assembly Lord Mayor Peter Estlin London boroughs (list) Vacant The government passed the Greater London Authority Act 1999, creating the Greater London Authority.