This paper examines the association of the presence of royal family members on the board of directors with audit committee effectiveness. The sample of this study consists of 444 listed manufactured firms in Saudi Arabia for the period 2012-2019. Using the Pooled OLS regression, the result of the study shows that royal family ownership is associated with audit committee effectiveness, giving support to the substitution hypothesis. The result indicates that members from the royal families are good monitors imposed into the companies' managements as both taking the role of decision makers and owners who may substitute the effectiveness of the audit committee. The presence of royal family members on the board has an alternative for the effectiveness of the audit committee. The marginal effect of audit committee effectiveness as an internal corporate governance mechanism is substituted by the presence of royal family members on the board. This study provides insightful evidence to regulators and policy makers at the company and country levels on the relationship of royal family ownership and audit committee effectiveness.