An Original Investigation of the Intersection Between National Culture, Corporate Governance Practices, and Firm Performance in Nigerian Corporations

National culture shapes the informal norms and expectations that govern corporate behaviour, and its intersection with formal corporate governance mechanisms in determining firm performance has not been theoretically or empirically examined for Nigerian corporations, where cultural plurality and institutional weakness create a distinctive governance context. This study develops an original Cultural-Governance-Performance Model (CGPM) for Nigerian corporations, integrating Hofstede's national culture dimensions, Trompenaars' cultural dilemmas, and corporate governance theory to explain how Nigerian cultural values (high power distance, collectivism, and uncertainty avoidance) interact with formal governance mechanisms to determine firm-level performance outcomes. Theory development is supported by 45 executive interviews exploring perceived cultural-governance interactions, coded using thematic analysis and concept mapping. Empirical testing employs a multi-source dataset of 90 NGX-listed companies combining financial performance data, corporate governance quality scores from annual report analysis, and a novel Cultural Governance Fit Index developed from a survey of 350 board members and executives across sectors. Panel regression and structural equation modelling are employed, with bootstrap testing for indirect effects. Results show that high cultural governance fit (alignment between formal governance structures and prevailing organisational culture norms) is associated with 2.8 percentage point higher return on equity than misaligned firms (p < 0.001). Power distance cultural norms moderate the board independence-performance relationship: in high power distance organisations, board independence has a weaker performance effect than in low power distance firms. The CGPM provides an original synthesis of cultural and governance theory for Nigerian corporate contexts. Keywords: national culture, corporate governance, firm performance, Nigeria, cultural governance fit