Summary Five Sustainable Development Goals (SDGs) set targets that relate to the reduction of health inequalities nationally and worldwide. These targets are poverty reduction, health and wellbeing for all, equitable education, gender equality, and reduction of inequalities within and between countries. The interaction between inequalities and health is complex: better economic and educational outcomes for households enhance health, low socioeconomic status leads to chronic ill health, and non-communicable diseases (NCDs) reduce income status of households. NCDs account for most causes of early death and disability worldwide, so it is alarming that strong scientific evidence suggests an increase in the clustering of non-communicable conditions with low socioeconomic status in low-income and middle-income countries since 2000, as previously seen in high-income settings. These conditions include tobacco use, obesity, hypertension, cancer, and diabetes. Strong evidence from 283 studies overwhelmingly supports a positive association between low-income, low socioeconomic status, or low educational status and NCDs. The associations have been differentiated by sex in only four studies. Health is a key driver in the SDGs, and reduction of health inequalities and NCDs should become key in the promotion of the overall SDG agenda. A sustained reduction of general inequalities in income status, education, and gender within and between countries would enhance worldwide equality in health. To end poverty through elimination of its causes, NCD programmes should be included in the development agenda. National programmes should mitigate social and health shocks to protect the poor from events that worsen their frail socioeconomic condition and health status. Programmes related to universal health coverage of NCDs should specifically target susceptible populations, such as elderly people, who are most at risk. Growing inequalities in access to resources for prevention and treatment need to be addressed through improved international regulations across jurisdictions that eliminate the legal and practical barriers in the implementation of non-communicable disease control.