More than a quarter of schools, nurseries and colleges are in areas with "dangerously high" levels of pollution that exceed global guidelines.
Research found 8,549 educational institutions in England, Wales and Scotland - some 27 per cent of the total - are located where the background level of tiny particle pollution known as PM2.5 exceeds international advisory levels.
The research commissioned by Asthma UK and the British Lung Foundation compares the location of schools, nurseries and colleges with annual PM2.5 levels in those areas, in 2019, before the impact of lockdown.
Analysis from Cambridge Environmental Research Consultants highlights how many establishments are in areas where PM2.5 pollution exceeds World Health Organisation limits - which are tougher than UK rules.
Some of the highest levels of PM2.5 are in Portsmouth, London, Gillingham, Camberley, Chatham and Slough, which all had schools in areas above the WHO guidelines.
Liverpool, Manchester and Birmingham all have individual schools in areas well above the guideline values, Asthma UK and the British Lung Foundation said.
Air pollution is blamed for tens of thousands of early deaths in the UK each year, is associated with lung disease and cancer, and can trigger conditions such as asthma.
Asthma UK and the British Lung Foundation want to see the Government commit to safer new legal limits.
Harriet Edwards, senior policy and project manager for air quality at Asthma UK and the British Lung Foundation, said: "It's alarming that thousands of children are going into schools where dangerously high air pollution levels could be putting their health and futures at risk.
"There are no safe levels for air pollution, we need to get levels as low as possible and it's vital the Government commits to ambitious new targets in line with the best available science from the WHO."
