Educational attainment is an important social determinant of maternal, newborn, and child health. As a tool for promoting gender equity, it has gained increasing traction in popular media, international aid strategies, and global agenda-setting. The global health agenda is increasingly focused on evidence of precision public health, which illustrates the subnational distribution of disease and illness; however, an agenda focused on future equity must integrate comparable evidence on the distribution of social determinants of health. Here we expand on the available precision SDG evidence by estimating the subnational distribution of educational attainment, including the proportions of individuals who have completed key levels of schooling, across all low- and middle-income countries from 2000 to 2017. Previous analyses have focused on geographical disparities in average attainment across Africa or for specific countries, but — to our knowledge — no analysis has examined the subnational proportions of individuals who completed specific levels of education across all low- and middle-income countries. By geolocating subnational data for more than 184 million person-years across 528 data sources, we precisely identify inequalities across geography as well as within populations.