With the continued rise of emissions and illegal levels of pollution in many places, air quality is increasingly recognised as a serious public health issue. Cities are primarily affected and policy makers have come under increasing pressure from voters, campaigners and health professionals to find solutions to reduce emissions. In response to the issue, the Government published a plan in July 2017 to tackle roadside nitrogen dioxide emissions which gives responsibility to local authorities to clean up their air. Around the world and in the UK, London and other cities are already showing leadership by undertaking measures to tackle air pollution. This briefing presents the geography of air quality in the UK and introduces examples of cities’ good practice to help UK cities better understand what they can do to improve air quality locally.