This book explores the relationship between stock prices and financial performance in the banking sectors of the United Kingdom (UK) and Nigeria from 2018 to 2022. The study's context arises from the noteworthy role that these banking industries fulfil in their corresponding economies, facilitating financial intermediation, capital allocation, and economic expansion. The study seeks to offer valuable insights for investors, policymakers, regulators, and academics by examining the relationship between stock prices and financial performance indicators like Return on Equity (ROE), Return on Assets (ROA), and Net Interest Margin (NIM). The UK's banking sector is renowned for its stability and regulatory framework, while Nigeria's sector has experienced significant changes and regulatory adjustments. The study recognizes that each country's distinct economic circumstances, regulatory structures, and market forces play a vital role in shaping the relationship between stock prices and financial performance. This study addresses the critical issue of the need for comprehensive empirical research examining the relationship between the UK and Nigerian banking sectors.