Outdoor mobility is important for the well-being of older adults and is influenced by individual and environmental factors. The purpose of this study was to investigate the individual resources, environmental factors, and activity destinations that contribute to the out-of-home mobility of older adults. This dissertation is based on datasets from two research projects: Life-Space Mobility in Old Age (2012; n = 848, and 2016; n = 206); and Active Ageing – Resilience and External Support as Modifiers of the Disablement Outcome (2017– 2018; n = 901, and 2021–2022; n = 613). The participants were community dwelling people aged 75 to 90 living in Central Finland. Self-reported 2-km walking difficulties, physical activity, sense of autonomy, and participation in leisure activities were assessed in home interviews. Visited destinations (physical exercise, attractive, regular) were collected using the Public Participation Geographic Information System (PPGIS) questionnaire. A neighborhood walkability index, the land use type around the destination, and the distance to the destination were calculated using geospatial datasets. The older adults living in the highest walkability area had higher odds for frequent participation in cultural and individual activities and lower odds for participation in outdoor activities than those living in the lowest walkability area. Reporting intact walking or walking modifications was associated with frequent participation in leisure activities and a higher number of activity destinations and destinations located further away from home. The older adults reporting higher physical activity used a larger variety of physical exercise destinations and destinations located further away from home than those reporting lower physical activity. Visiting a lower number of activity destinations and destinations located closer to home was associated with a more restricted sense of autonomy outdoors.