Engagement in recommended levels of physical activity decreases dramatically with age, despite many health and social benefits. Effective implementation of physical activity services for older adults requires that such provision is acceptable to them. Older adults living in deprived areas, where lack of resources can result in unmet basic needs, are twice as likely to be inactive as those in more affluent areas, suggesting lower levels of acceptability of leisure time physical activity. Older adults with lower socioeconomic status also experience greater barriers to physical activity yet are often omitted from research. Acceptability is often conceptualised as the level of tolerance required to undertake health behaviours in order to gain future health-related benefits. As many older adults may view physical activity as irrelevant, a waste of limited resources, or a luxury that only the well, or well-off, can indulge in, an alternative approach may be more fitting. The term acceptability can also be used to denote how attractive health behaviours are perceived to be to the target audience, and whether or not they are actively sought out. When viewed through this lens, physical activity may be seen as an enjoyable way to spend time connecting with others, whilst still reaping the many benefits for health and wellbeing. This PhD aimed to address the gap in knowledge on the role acceptability of physical activity plays in the engagement in physical activity by older adults and to explore the impact of socioeconomic factors on such acceptability. A meta-synthesis was conducted to identify underlying reasons older adults have for wanting to engage in physical activity (or not). Few data were found from low socioeconomic status areas. The impact of providers views on acceptability were rarely considered in the literature. A multi-perspective interview study was therefore conducted within low socioeconomic status areas to explore acceptability of physical activity in this context. Views on what made physical activity acceptable to older adults (with reasons for such acceptability) were elicited both from older adults in low socioeconomic status areas and from providers of physical activity programmes in these locations. This study resulted in two papers, one published paper on the conflation of time and energy from the older adults' perspective, and one paper (in preparation) on the wider multi-perspective views of older adults and providers on the acceptability of physical activity. A published book chapter giving an overview of how to implement these findings to make physical activity interventions more acceptable to older adults completes this research. Focusing on fun and enjoyment rather than long-term health outcomes within physical activity services does appear more acceptable to many older adults. Actively encouraging socialising by providing time and space around and within physical activity increases the value to many and may be particularly important in deprived areas where there may be limited other opportunities for socialising. Providers may need to think outside their remit or work collaboratively with those from other sectors to achieve this multi-functional physical activity/social provision in order to encourage older adults in deprived areas into what could otherwise be an unfamiliar concept, leisure time physical activity. Encouraging socialising within physical activity can be an effective use of limited resources, increasing acceptability of physical activity as a by-product of satisfying highly valued social needs.