A natural capital account for public green space in London was commissioned by the Greater London Authority, National Trust and Heritage Lottery Fund to estimate the economic value provided by London’s public parks. The account highlights the enormous economic value and benefits provided by public parks and green spaces. It provides an evidence base for maintaining and increasing investment in London’s public green spaces, and motivates policy-makers and decision-makers to explore new sustainable models for funding or financing the provision and maintenance of public parks. It was found that London’s public parks have a gross asset value in excess of £91 billion. For each £1 spent by local authorities and their partners on public parks, Londoners enjoy at least £27 in value. However, the economic benefits from parks are not spread equally across or within London’s boroughs. Some parts of London benefit from having plentiful green spaces, whilst others are lacking in this important resource. This natural capital account helps to highlight these inequalities so that future investments can be targeted spatially to help correct inequalities.