Objective: To examine the associations between ADHD and social functioning and participation among older adults. Method: Data were used from the Longitudinal Aging Study Amsterdam (LASA). In 2008/2009, respondents were asked about social functioning and participation. A diagnostic interview to diagnose ADHD was administered among a subsample (N = 231, age 60-94 years). ADHD diagnosis and level of ADHD symptoms were assessed. Results: ADHD diagnosis was associated with being divorced/never married, having less family members in their network, and emotional loneliness. Level of ADHD symptoms was associated with more emotional support given, emotional and social loneliness, greater recreational social participation, and lower income level. Conclusion: This study shows that ADHD in old age is related to being divorced/never married and loneliness but not to work participation. Psycho geriatric practices should direct their attention to loneliness when treating ADHD.