As cyber threats intensify globally, traditional perimeter-based security models have proven inadequate, especially in digitally evolving nations. Zero-Trust Architecture (ZTA), which operates on the principle of “never trust, always verify,” offers a paradigm shift by enforcing granular access controls, continuous authentication, and stringent verification of user and device identities. While ZTA has gained momentum in developed economies, its application in emerging economies remains underexplored. This paper investigates the feasibility, challenges, and strategic benefits of deploying ZTA in Nigeria, a representative emerging economy experiencing rapid digital transformation amid complex cybersecurity vulnerabilities. The study begins with a review of Nigeria’s digital infrastructure, regulatory environment, and threat landscape, highlighting issues such as fragmented IT ecosystems, weak enforcement of cybersecurity policies, and limited technical capacity in public institutions. A detailed case study of a Nigerian financial services provider transitioning to a Zero-Trust model is presented, focusing on network segmentation, identity governance, multi-factor authentication, and endpoint security. The deployment leveraged cloud-native tools and identity-as-a-service platforms to minimize cost while ensuring scalability. Findings suggest that while Zero-Trust significantly improves security posture and resilience against insider threats and ransomware, its implementation is hindered by legacy systems, cultural resistance to access restrictions, and limited skilled manpower. Nevertheless, with targeted investment in cybersecurity skills, stakeholder engagement, and adaptive policy frameworks, ZTA can be successfully localized in resource-constrained environments. The paper concludes with a set of policy and technical recommendations tailored for emerging economies seeking to adopt Zero-Trust as part of their digital security modernization.