The Global Urban Demographic Dataset (GUDD) provides city-level and country-context demographic information for analyzing urban population change, dependency patterns, and migration-related demographic divergence. It includes metrics such as population structure, dependency indicators, population pyramids, and snapshot measures that can be explored by city, country, region, income status, and year. The dataset supports comparative research on how urban populations differ across global contexts and how demographic profiles evolve, enabling applications in urban studies, population geography, migration analysis, planning, and policy assessment.