This review paper explores the theoretical underpinnings and practical applications of blockchain technology within the banking sectors of African and U.S. financial institutions. It delves into key theoretical constructs such as Distributed Ledger Technology (DLT), smart contracts, and cryptographic security, examining their potential to revolutionize banking operations through enhanced efficiency, security, and transparency. The paper contrasts the applications and challenges faced by banks in Africa and the U.S., highlighting the unique opportunities and hurdles in each region. Regulatory environments, technological barriers, and market potential are critically analyzed to understand the landscape of blockchain adoption in banking. The review underscores the transformative potential of blockchain in banking while suggesting areas for future research aimed at overcoming challenges and harnessing emerging opportunities for innovation and growth in the sector.