Regular physical activity is one of the key components of a healthy lifestyle. It is associated with better physical and cognitive functioning in later life and with increased life expectancy. The purpose of this study was to evaluate the prevalence of, and factors related to, physical inactivity among older adults across Europe. in this cross-sectional analysis, we used data from participants aged 55 or older in Wave 4 of the Survey of Health, Ageing, and Retirement in Europe (SHARE) database, a multidisciplinary and cross-national panel database covering health, socioeconomic status, and social and family networks. Individuals included in this study were classified as physically active or physically inactive. Clinical, psychosocial and sociodemographic variables were evaluated for their association with physical inactivity. from the total of 58,489 individuals in SHARE, we selected 19,298 people age 55 or older (mean age 67.8 ± 8.9 years; 11,430 (59.2%) female). The overall prevalence of inactivity among individuals age 55 or older in the 16 included countries was 12.5%. The prevalence of physical inactivity varied between countries, ranging from 4.9% (Sweden) to 29% (Portugal). Increasing age, depression, physical limitations, poor sense of meaning in life, social support and memory loss were significant variables associated with physical inactivity. physical inactivity can be explained by physical, cognitive and psychological conditions. Interventions aimed at promoting physical activity among older people are needed to address this diversity of factors.