Mobile phones are recognized as a primary platform for mitigating the digital divide and increasing economic growth, and the same appears to be true for Nigeria, the largest economy in Africa. Since 2012, mobile phone penetration has shown nearly linear growth, reaching 83% in 2016. However, this statistic falls to only 46% after correcting for ownership of multiple SIM cards and sharing of mobile phones among multiple users. The determinants of mobile phone ownership in Nigeria are poorly understood, which hinders research that could inform policies capable of increasing mobile phone penetration and eliminating the digital divide. To begin to fill this research gap, we have analyzed socio-economic factors related to mobile phone ownership in the country. We used a logit model and the latest national-level Datafirst ICT dataset (2012) about mobile phone adoption from 1552 individuals. The sample was stratified, clustered, and probability-weighted to make it representative of the situation at the national level. The results suggest that factors such as geographic location and income may not strongly influence mobile phone ownership, in contrast to what was previously thought. Instead, the strongest factors appeared to be education level, informal work, social engagement, type of electricity supply and employment status. Our analysis suggests that to increase mobile phone ownership and close the digital divide, policy makers should target younger adults, provide training in digital literacy specifically for mobile phone use, invest in electricity supply infrastructure, and develop content and applications in non-English languages. These findings may contribute to understanding mobile phone distribution in Nigeria as well as inform implementation of the country's ICT Roadmap 2017–2020 and Vision 2020.