The supportive role of urban spaces in active aging is explored on a world scale in this unique resource, using the WHO’s Age-Friendly Cities and Community model. Case studies from the U.S., Canada, Australia, Hong Kong, and elsewhere demonstrate how the model translates to fit diverse social, political, and economic realities across cultures and continents, ways age-friendly programs promote senior empowerment, and how their value can be effectively assessed. Age-friendly criteria for communities are defined and critiqued while extensive empirical data describe challenges as they affect elders globally and how environmental support can help meet them. These chapters offer age-friendly cities as a corrective to the overemphasis on the medical aspects of elders’ lives, and should inspire new research, practice, and public policy. • A critical review of the WHO Age-Friendly Cities Methodology and its implementation. • Seniors’ perspectives on age-friendly communities. • The implementation of age-friendly cities in three districts of Argentina. • Age-friendly New York City: a case study. • Toward an age-friendly European Union. • Age-friendliness, childhood, and dementia: toward generationally intelligent environments.