This paper examines the impact of the government and its agencies’ ownership on the effectiveness of one the main internal governance mechanisms, namely; board of directors, for a sample of 140 energy and petrochemical Saudi listed firms over 2012-2019. The Saudi Arabia provides an interesting context due to the domination of government-linked corporations’ ownership. This setting arranges for the impact of such ownership on the board of directors’ monitoring and advisory roles. The board of directors’ effectiveness is measured as an interaction term of the board size and meetings of the board of directors. The study finds that government-linked energy and petrochemical corporations’ ownerships are inversely related to the board of directors’ effectiveness. This result is sensitive to the measurement of the board of directors’ effectiveness as each variable consisting of the board of directors’ effectiveness was examined individually. The study also finds that government-linked corporations’ ownership had a strong negative impact on the board size. In contrast, the proposed model does not provide any evidence supporting the relationship of the government-linked corporations’ ownerships with board meetings. Overall, the evidence supports the substitution hypothesis on the relationship of government-linked corporations and board of directors’ effectiveness.