Sarcopenia and osteoporosis are associated with morbidity and mortality. The development and progression of these two interrelated conditions are related to genetic and lifestyle factors, including nutrition and physical activity. Restrictions placed on individuals due to the COVID-19 pandemic and infection have led to widespread lifestyle modifications, with data suggesting a negative impact on physical activity levels. There is an urgent need to understand the effect of the pandemic on musculoskeletal health in older adults, at a time when COVID-19 infection and restrictions remain a barrier to research studies. We tested the feasibility of recruiting local community-dwelling older people to establish a new cohort investigating musculoskeletal health—the Southampton Longitudinal Study of Ageing (SaLSA). We invited 1993 community-dwelling older adults registered at the Living Well GP partnership in Southampton, UK, to participate in a study. Questionnaires were completed by participants on health, lifestyle, medication use, comorbidities, physical activity, nutrition, sarcopenia, osteoporosis, and quality of life. Permission was sought for future contact. Descriptive statistics were used on the initial pilot of 175 returned questionnaire data. The median age of participants was 80.4 years in both sexes, 81.3 years (77.9–84) in females, and 81.1 years in males (77.3–83.6). The majority (N = 168/171, 98%) of participants were of white Caucasian background; 36/53 (68%) female participants and 38/119 (32%) male participants lived alone. Over 80% (295/353) consented to be contacted for future studies. Recruitment of participants from a primary care practice into a research study was feasible. The next steps are to perform detailed musculoskeletal phenotyping through physical performance measures, grip strength dynamometry, DXA scanning, high-resolution peripheral quantitative computed tomography (HRpQCT), thigh ultrasound, and muscle biopsy, in a subset of participants. Our vision for SaLSA is to build a platform for discovery science and mechanistic studies, with the goal of improving the health care of older people.