Cities today face mounting challenges, from large-scale crises and climate change to the needs of aging populations. These forces profoundly shape human mobility, influencing how people move, interact, and access essential services. This talk examines the complex interplay between urban mobility, environmental justice, and social inequality, leveraging research on mobility data, air quality exposure, and accessibility disparities. Through case studies such as the BostonWalks study, we explore how movement patterns contribute to unequal pollution exposure, disparities in service access, and resilience to external shocks like COVID-19 and extreme weather events. By integrating mobility analytics with environmental and demographic data, we reveal structural inequities in urban spaces, highlighting how marginalized communities often bear a disproportionate burden. This discussion will showcase key findings on mobility rhythms, environmental disparities, and aging populations' access to critical services, providing a data-driven lens to understand and address urban inequality.