Due to the ubiquity of mobile phones around the globe, studies are beginning to analyze their influence on health. Prior work from developed countries highlights negative mental health outcomes related to overuse of mobile phones. However, there is little work on mental health impacts of mobile phone use or ownership in developing countries. This is an important gap to address because there are likely variations in mental health impacts of mobile phones between developing and developed countries, due to cultural nuances to phone use and distinct variations in financial models for obtaining mobile phone access in developing countries. To address this gap, this study analyzes survey data from 92 households in sparse, rural villages in Uganda to test two hypotheses about mobile phone ownership and mental health in a developing country context: (i) Mobile phone ownership is higher among more privileged groups, compared to less privileged groups (ie, wealth and ethnicity); and (ii) mobile phone ownership is positively associated with a culturally-relevant indicator of mental health, 'feelings of peace'. Results indicate that households with mobile phones had higher levels of wealth on average, yet no significant differences were detected by ethnicity. As hypothesized, mobile phone ownership was associated with increased mental well-being for persons without family nearby (in the District) (p = 0.038) after adjusting for wealth, ethnicity and amount of land for crops and land for grazing. Mobile phone ownership was not significantly associated with increased mental well-being for persons with family nearby. These findings are consistent with studies of mobile phone use in other sub-Saharan African countries which find that phones are important tools for social connection and are thus beneficial for maintaining family ties. One might infer then that this increased feeling of mental well-being for persons located farther from family stems from the ability to maintain family connections. These findings are quite different from work in developed countries where mobile phone use is a source of technology-related stress or technostress.