Associations of objectively-assessed neighborhood environment characteristics with accelerometer-based physical activity (PA) and sedentary time, and their socio-demographic and health-status moderators were examined. Data were collected on 402 Hong Kong Chinese older adults from neighborhoods stratified by socio-economic status and transport-related walkability. Few main effects were observed. Sex moderated a third of the associations of environmental attributes with light-to-vigorous PA and sedentary time. Education and car ownership also moderated several associations with moderate-to-vigorous PA, light-to-vigorous PA, and sedentary time. Only two associations depended on age and health-related status. These findings suggest that social factors rather than physical capacity and health status may need to be considered in efforts to optimize activity-friendly environments for Chinese older urban dwellers.