Digital libraries play a crucial role in closing information access gaps, fostering educational equity, and promoting lifelong learning, particularly in developing countries facing infrastructural and socio-economic constraints. Despite their transformative potential, the adoption of digital libraries in these contexts remains limited due to a variety of persistent challenges. The existing literature on this topic is often fragmented and lacks comprehensive, comparative analysis especially between countries with similar developmental contexts. This review addresses this gap by systematically synthesizing findings from 24 empirical and theoretical studies, focusing on India and Nigeria. The analysis identifies six major categories of influencing factors: technological, human, organizational, cultural, financial, and comparative insights. Common technological barriers include outdated ICT infrastructure and platforms that are not optimized for mobile use. Human-related issues such as low digital literacy, technophobia, and resistance to change also obstruct adoption. Institutionally, Nigeria suffers from weak policy frameworks and limited funding, in contrast to India’s more centralized programs like INFLIBNET and NDLI. Cultural and social elements, including language diversity and a continued preference for print materials, add further complexity. Financially, the high cost of devices and internet access limits both individual and institutional participation. Though India and Nigeria share many of these barriers, India benefits from national coordination, whereas Nigeria’s progress is more decentralized and inconsistent. The review underscores the urgent need for inclusive policies, sustainable funding, digital skill development, and context-appropriate technologies. It also identifies gaps in the literature, such as a lack of longitudinal studies and limited attention to marginalized user groups, offering guidance for future research and policy planning.