Background: Older adults living in nursing homes spend the majority of their time inactive. The associated levels of chronic disease place an increasing burden on healthcare systems. Physical activity (PA) interventions delivered through exercise classes may be resource-intensive and require specialist staff. The aim of this study is to explore the feasibility and acceptability of a PA programme embedded into the daily lives of older adults living in nursing homes and to examine the preliminary effects of this on physical mobility and quality of life.Methods: A randomised controlled pilot feasibility study, including embedded qualitative and economic components will be carried out. Two randomly selected nursing homes will take part in the study; participants (n = 20) in one nursing home will receive a three-month PA intervention and participants (n = 20) in the other will be a usual care control. Nursing home staff will be provided with training and support to monitor participants PA programmes. Feasibility data will be collected on recruitment, randomisation, assessment and intervention procedures. Criteria for progression of the pilot feasibility study to a definitive trial will be specified. The Timed Up and Go test, Nottingham Health Profile, 10-Metre Walk test, the Investigating Choice Experiments for the Preferences of Older People Capability index and the Bangor Goal Setting Interview will be assessed at baseline, three-month and 12-month follow-up. Between-group and within-individual effects will be estimated using appropriate linear mixed models. Semi-structured interviews will be conducted with staff and participants of the intervention group within one month after the intervention to explore the feasibility and acceptability of the programme. A subset of control participants will be interviewed to describe usual care. Economic data will be collected to examine costs of the intervention in comparison with costs in the control group.Discussion: The findings will facilitate refinement of the PA programme and development of a clear protocol for subsequent evaluation of the PA intervention in a definitive randomised controlled trial.