Corporate governance structures in emerging African economies have undergone significant transformation, influenced by global standards and local socio-economic pressures. The interplay between these governance frameworks and market dynamics remains a critical but underexplored area, particularly in the West African context. This study aims to compare the evolution of corporate governance mechanisms and their impact on market efficiency, investor behaviour, and firm valuation. It seeks to identify the dominant governance models and analyse their correlation with key market performance indicators over an extended period. A longitudinal comparative analysis was conducted using a mixed-methods approach. Quantitative data from listed firms' financial reports and market indices were analysed alongside qualitative data from regulatory documents and expert interviews. The study employs panel data regression and thematic analysis. A pronounced shift from family-dominated to more institutional governance models was observed, correlating with improved market liquidity. Firms adopting integrated reporting demonstrated a 15% higher average price-to-book ratio than peers. However, regulatory enforcement was identified as a persistent challenge, tempering the efficacy of formal governance codes. The formal adoption of international governance standards has positively influenced market dynamics, but their effectiveness is substantially mediated by local institutional quality and enforcement capacities. The convergence towards hybrid governance models appears most sustainable. Policymakers should prioritise strengthening regulatory enforcement mechanisms over further legislative reform. Firms are encouraged to adopt integrated reporting and enhance board independence, particularly for audit and remuneration committees. corporate governance, market efficiency, institutional investors, emerging markets, regulatory enforcement, behavioural finance This paper provides a novel longitudinal dataset tracking governance and market metrics, and introduces a framework for analysing the behavioural pathways through which governance perceptions affect market participation in an emerging African economy.