This case study examines the role of mobile technology and digital literacy in improving maternal healthcare access for adolescent girls in Niger, a Sahelian country with some of the world's highest rates of adolescent pregnancy and maternal mortality. It investigates whether mobile phone ownership and the competencies to use it effectively can increase antenatal care attendance, skilled birth attendance, and postnatal care utilisation. Using a concurrent mixed-methods design, the research analysed quantitative survey data from 450 adolescent mothers across three regions, gathered in 2023–2024, supplemented by qualitative focus group discussions with a subset of participants and local health workers. Key findings reveal that while mobile phone ownership alone had a limited association with improved health-seeking behaviours, digital literacy—defined as the ability to find health information, communicate with providers, and navigate relevant applications—was the most significant factor. Adolescents with higher digital literacy were 2.3 times more likely to complete the recommended four antenatal visits. However, structural barriers such as unstable network coverage, costs, and prevailing socio-cultural norms substantially mediated this effect. The study concludes that for mobile health (mHealth) initiatives in Niger and similar contexts to be effective, they must be integrated with targeted digital literacy programmes aimed at adolescent girls. Such an integrated strategy is crucial for harnessing technology as a genuine tool for health equity and advancing Sustainable Development Goal targets for maternal health.