The objective of this paper is to determine the relationship between the Chief Audit Executive's (CAE) leadership style and senior management support for the internal audit function (IAF) as determinants of IAF quality and corporate governance (CG) effectiveness in Yemeni commercial banks. This article also investigates the extent to which the characteristics of the audit committee (AC) influence the link between CAE leadership style, support senior management for IAF, and CG effectiveness. The data was acquired using questionnaires delivered to respondents in Yemeni commercial banks, of which 158 valid questionnaires were obtained for analysis. Smart PLS 3 was used to analyse the data and test the hypotheses. The PROCESS macro approach was also utilised to evaluate the influence of AC characteristics on the association between CAE leadership style, senior management support for IAF, and CG effectiveness. An affirmative substantial correlation was found between CAE leadership style and senior management support for IAF, and CG effectiveness. Furthermore, the study found that AC characteristics favourably influence the association between CAE leadership style and CG effectiveness. However, AC characteristics do not alter the association between senior management support for the IAF and CG effectiveness. The findings improve the IAF's quality of determinants to enhance CG in developing countries, such as Yemen.