Objective: To investigate the impact of objective and subjective social isolation from extended family members and friends on depressive symptoms and psychological distress among a national sample of older adults. Method: Data for older adults (55 years and above) from the National Survey of American Life (N = 1,439) were used to assess level of objective social isolation and subjective social isolation and to test regression models examining their impact on depressive symptoms (Center for Epidemiologic Studies Depression [CES-D] Scale) and psychological distress (Kessler 6 [K6] Scale). Results: The majority of respondents were not socially isolated from family or friends; 5% were objectively isolated from family and friends, and less than 1% were subjectively isolated from family and friends. Regression analyses using both social isolation measures indicated that objective social isolation was unrelated to depressive symptoms and psychological distress. However, subjective social isolation from both family and friends and from friends only was associated with more depressive symptoms, and subjective social isolation from friends only was associated with higher levels of psychological distress. Discussion: Assessments of social isolation among older populations should account for both subjective and objective dimensions, as well as both family and friend social networks. Social isolation from friends is an important, but understudied, issue that has significant consequences for older adult mental health.