Objective: Social frailty is related to adverse health-related outcomes. However, the measurement thereof is controversial and research into the relationship between social frailty and physical functioning remains limited. This study aimed to determine social frailty status via developing a simple self-reported screening tool, termed the HALFT scale, and to examine the association between social frailty and physical functioning, cognition, depression, and mortality among community-dwelling older adults. Design: Prospective cohort study. Setting: Community. Participants: 1697 community-dwelling adults aged 60 years from Beijing Longitudinal Study of Aging were included. Measurements: The HALFT scale was developed based on 5 items: unhelpful to others, limited social participation, loneliness, financial difficulty, and not having anyone to talk to. Socioeconomic and demographic data were collected, and physical functioning, frailty index, cognition, and depression were assessed. Results: The prevalence of social frailty was 7.7% (weighted, 4.5%). Participants with physical frailty, low levels of physical activity, and poor physical functioning had a higher prevalence of social frailty. Social frailty was associated with dementia, subjective memory decline, depression, cognitive impairment, and having experienced a recent significant life event. After adjusting for age and sex, the 8-year mortality hazard ratios were 2.5-4.3 and 1.6-2.3, respectively, for those with social frailty or pre-social frailty. Each component of the HALFT scale predicted 8-year mortality. Conclusion: Social frailty is associated with physical functioning, cognition, and depression, and predicts mortality. The HALFT scale could be a useful screening tool for determining social frailty in older adults. Interventions aimed at preventing or delaying social frailty are warranted.