We use survey data on 170,000 households from Asia, Latin America and Africa, global geo-spatial data, and an economic geography framework to highlight five findings about rural youth in developing countries. First, the youth share in population is falling rapidly, and youth numbers are stable or falling slowly everywhere, except in Africa. In Africa, youth share is rising very slowly, but numbers are set to double in 40 years. Second, large majorities of rural youth live in spaces that are not inherently limiting: two-thirds live in zones with highest agricultural potential, and one-quarter combine this with highest commercialisation potential. The 4% that do live in inherently challenging spaces are concentrated in pockets of persistent poverty in middle-income countries. Third, rural spaces’ commercial potential has large impacts on welfare outcomes, but their agricultural potential has no detectable impact. Fourth, households with young members face income- and poverty ‘penalties’ in all regions and spaces within them, compared to households without young members. The poverty penalty declines sharply over space as commercial potential rises, but the income penalty shows ambiguous patterns. Fifth, households with young members earn lower relative returns to education, with varying patterns over space.