The Seniors Exercise Park program is an evidence-based outdoor physical and social activity program designed originally for older people with no cognitive impairment. This study aimed to pilot this program for people living with dementia in residential aged care. We examined the feasibility of delivering the program, evaluating its structure, safety, and supervision needs. In addition, physical, social, health and cognitive benefits of participation were examined. Method This was a feasibility pilot randomised controlled design. Adults aged ≥ 60 years with symptoms of dementia and/or diagnoses of dementia were recruited from an aged care facility in Australia. Participants allocated to the intervention underwent a 12-week structured supervised physical activity program using the outdoor Seniors Exercise Park equipment followed by a 12-week maintenance phase, while the controls received usual care programs. Assessments occurred at baseline, 12 and 24-weeks. Feasibility evaluation included recruitment rate, retention, attendance, overall adherence, dropout rate, adverse events, program delivery modifications and supervision requirements. A suite of cognitive and health-related questionnaires and physical function measures were also collected. Results Sixteen participants were recruited (recruitment rate: 58.6%), eight for the intervention (83.3 ± 7.5 years, 87.5% women) and eight for the control (age 87.5 ± 3.0 years, 87.5% women). Eighty-eight percent completed the 12-week structured program, with 75% retention at 24-weeks. Across the 24-week period, 84.3% participation adherence was reported. No falls or adverse events occurred. Modifications of the program mainly related to method of communication, cueing and adjustments to suit individual personality and characteristics. A ratio of one trainer to two participants was practical and safe. There were no significant changes over time between groups in any of the secondary outcomes. High level of engagement, enjoyment and mood was reported throughout the exercise program. Conclusion The Seniors Exercise Park physical activity program was safe and feasible for people living with dementia in residential care, with high levels of enjoyment, positive attitude, and engagement reported in the intervention group. Individualised communication during program delivery was needed to facilitate motivation and participation. Further research is needed to assess the program effectiveness on physical and cognitive function on a larger scale. Trial registration This trial is registered with the Australian New Zealand Clinical Trials Registry-Registry Number ACTRN12620000733976 . Registered on the 13/07/2020.