Background and Aim: Active or healthy ageing is the process of optimizing opportunities for health, participation, and security to enhance the quality of life as people grow old. It emphasizes the full realization of individuals and communities and their potential for physical, mental, spiritual, and social well-being throughout their life course, enabling them to remain engaged in their society fulfilling their needs and preferences with optimum support, protection, and care. Older adults residing in elderly care homes are particularly vulnerable to poor ageing outcomes due to a range of structural and psychosocial factors. While various global models for active ageing exist, their socio-cultural relevance and contextual adaptability in Sri Lankan care home settings remain untested. Therefore, we report findings of a study aimed to design, implement, and evaluate a contextually appropriate community-based health promotion intervention to enhance active ageing among older adults in an elderly care home in the Colombo District, Sri Lanka. Methodology: We explored the views and experiences of older adult residents and their caregivers in a selected elderly care home regarding active ageing, to understand the current situation. The health promotion intervention was conducted over 3 months and followed a structured three-phase approach: initiation, maintaining and directing toward effectiveness, and monitoring and modification for improvement. A community-centered, health promotion intervention model was adapted to develop a contextually appropriate logical framework (Fig. 1). Process and Outcomes: All participants were actively involved in the process. They identified the importance of healthy ageing and set a collective goal to create an environment that facilitate active ageing within their care home. With minimal facilitation, they were able to prioritize the factors that contribute to healthy ageing and then designed and carried out potentially beneficial activities to promote active ageing. Researchers used several data collection methods such as group discussions, observations, interviewer-administered questionnaires, reflective journals, and simple monitoring tools created by older adults and care home staff (e.g., happiness calendar, activity calendar) to assess outcomes and monitor progress periodically. Activities designed and implemented include regular exercises, gardening, measuring happiness, engaging in hobbies and leisure activities, and group works to increase interaction among residents. The intervention led to notable positive changes in attitudes, behaviors, and daily routines of both older adults and care staff, facilitating a healthy, age-friendly environment within the care home. The noteworthy changes are an increased level of physical activities, enhanced motivation to conduct daily exercises, gardening and new learning, improved happiness and interactions among residents, and reduced sedentary behavior such as prolonged TV watching, daytime sleeping, and sitting. Conclusion and Recommendation: The health promotion intervention significantly improved the care home environment, fostering active participation and collaboration between residents and staff, contributing to the creation of a more supportive, and engaging setting for healthy ageing. The health promotion approach is effective in empowering individuals and communities to initiate and sustain meaningful, long-term changes in health and well-being.