BACKGROUND: Living alone may be associated with greater risk for social isolation and loneliness. Living alone, social isolation, loneliness, and limited engagement in social activity have all been associated with poorer cognitive function in later life. Hence, if individuals who live alone are also at greater risk of isolation and loneliness, this may exacerbate poor cognitive function. OBJECTIVE: To determine whether people living alone are more at risk of social isolation, feelings of loneliness, and limited social activity, and to examine the associations between living alone and cognitive function in later life. METHOD: Baseline (N = 2197) and two-year follow-up (N = 1498) data from community-dwelling participants, age ≥65 years, without cognitive impairment or depression at baseline from CFAS-Wales were used. Linear regression analyses were conducted to assess the association between living arrangement and cognitive function at baseline and two-year follow-up. RESULTS: People living alone were more isolated from family and experienced more emotional loneliness than those living with others, but were not more isolated from friends, did not experience more social loneliness, and were more likely to engage in regular social activity. Living alone was not associated with poorer cognitive function at baseline or two-year follow-up. DISCUSSION: These findings have positive implications and suggest that people who live alone in later life are not at greater risk of poor cognitive function at baseline or two-year follow-up. Social isolation may be more associated with poor cognitive function.