Older adults aged 50 years and over may experience varied participation levels in out-of-home activities and travel modes, with their ability to walk being a significant factor. However, the heterogeneity of the activity–travel patterns of people at this age, especially in the Indonesian context, is not well understood. Using Yogyakarta as a case study and applying a latent class cluster analysis, this study is the first to categorize older adults’ participation in activities and use of travel modes and to understand the distinct characteristics of older adults. The model results revealed four discrete groups based on older adults’ activity participation and another four discrete groups based on their travel mode use. In the activity participation group, active older adults are the largest group, followed by inactive, working, and very active older adults. Meanwhile, those reliant on their motorized vehicles make up the largest travel mode group, followed by low-cost-vehicle users, captive riders of personal motorcycles, and car users. The model results also reveal that captive riders of personal motorcycles tend to be male and the youngest-old, while smartphone users are more likely to belong to the car users group. Walking ability constraints also significantly affect heterogeneity in older adults’ activity and travel mode, where those with no constraints on their ability to walk tend to be categorized as active older adult car users. The findings of this study may help policymakers identify older people with particular activity patterns and travel modes and develop policies to accommodate their mobility needs.