Social isolation and loneliness are increasingly prevalent among older adults in the United States, with implications for morbidity and mortality risk. Little research to date has examined the complex person-place transactions that contribute to social well-being in later life. This study aimed to characterize personal and neighborhood contextual influences on social isolation and loneliness among older adults. Interviews were conducted with independent-dwelling men and women (n = 124; mean age 71 years) in the Minneapolis metropolitan area (USA) from June to October, 2015. A convergent mixed-methods design was applied, whereby quantitative and qualitative approaches were used in parallel to gain simultaneous insights into statistical associations and in-depth individual perspectives. Logistic regression models predicted self-reported social isolation and loneliness, adjusted for age, gender, past occupation, race/ethnicity, living alone, street type, residential location, and residential density. Qualitative thematic analyses of interview transcripts probed individual experiences with social isolation and loneliness. The quantitative results suggested that African American adults, those with a higher socioeconomic status, those who did not live alone, and those who lived closer to the city center were less likely to report feeling socially isolated or lonely. The qualitative results identified and explained variation in outcomes within each of these factors. They provided insight on those who lived alone but did not report feeling lonely, finding that solitude was sought after and enjoyed by a portion of participants. Poor physical and mental health often resulted in reporting social isolation, particularly when coupled with poor weather or low-density neighborhoods. At the same time, poor health sometimes provided opportunities for valued social engagement with caregivers, family, and friends. The combination of group-level risk factors and in-depth personal insights provided by this mixed-methodology may be useful to develop strategies that address social isolation and loneliness in older communities. •Social isolation and loneliness are influenced by personal and neighborhood factors.•Qualitative findings explain variations in trends identified in quantitative models.•Poor health can have both negative and positive effects on social isolation.•Some socially isolated older adults seek solitude and are content, not lonely.•Results are relevant for strategies to address social isolation and loneliness.