The paper discusses the role of CubeSats in advancing sustainable cities and communities, emphasizing their value in urban monitoring. CubeSats, small and cost-effective satellites, enable near-real-time Earth Observation (EO), providing crucial geospatial data for managing urban environments. Their modular design facilitates flexibility in various applications. Organized in constellations, CubeSats can deliver high revisit frequencies, enhancing temporal resolution critical for dynamic urban analyses.<br />The study highlights the proliferation of CubeSats, including their distribution across countries and organizations, which now include private companies, universities, and non-profits, alongside traditional space agencies. Their affordability has democratized space access, enabling participation from developing nations and diverse institutions. Despite individual satellites’ limitations in spatial and temporal resolution, CubeSat constellations significantly improve urban EO data quality.<br />Key applications of CubeSats in urban settings include currently monitoring air quality, urban heat, vegetation health, and greenness, offering insights into public health and environmental well-being. Their utility spans urban planning, disaster management, and carbon sequestration.