This study presents a comprehensive review of Functional Data Analysis (FDA) in Health Informatics, focusing on a comparative analysis between the United States and Africa. The background of the study is rooted in the growing importance of FDA in the healthcare sector, driven by technological advancements and the increasing complexity of health data. The aim of the paper is to explore and contrast the developments, applications and challenges of FDA in health informatics within these two diverse geographical contexts. The scope of the paper encompasses the historical evolution, theoretical frameworks, technological advancements, structural differences in health data management and ethical considerations in both the USA and Africa. Methodologically, the study employs a qualitative analysis framework, integrating a systematic review of relevant literature. This approach facilitates an in-depth examination of the divergent paths and shared challenges in FDA across the two regions. The main findings reveal significant disparities in the evolution, application and effectiveness of FDA in health informatics. The USA demonstrates a leading role with advanced technological integration and innovative applications, while Africa shows resilience and adaptability despite facing challenges of limited resources and infrastructure. The study concludes that while the USA has made significant strides in utilizing data to enhance public health and healthcare delivery, Africa presents a landscape of both challenges and opportunities. The divergence is influenced by disparities in educational infrastructure, access to technological resources and healthcare delivery systems. Recommendations include the need for global collaboration, investment in health informatics education, workforce development and the establishment of global standards for health data analysis and sharing.