This study investigates the influence of corporate governance mechanisms specifically board size, board gender diversity, and audit committee independence on the timeliness of financial reporting, measured by audit report lag (ARL), among Indonesian non-financial companies. Using panel data from 718 firms listed on the Indonesia Stock Exchange (IDX) during 2019–2024 (totaling 3,587 observations), the analysis applies a fixed-effects regression model with Driscoll–Kraay standard errors to control for heteroscedasticity, autocorrelation, and cross-sectional dependence. The findings reveal that audit committee independence significantly reduces ARL, indicating that greater independence accelerates the reporting process. In contrast, leverage has a significant positive effect, implying that highly leveraged firms experience longer reporting delays. Meanwhile, board size, board gender diversity, profitability, and firm size show no significant influence on reporting timeliness. These results suggest that the effectiveness of governance mechanisms depends on their functional role rather than their structural presence. The study contributes to the corporate governance literature by highlighting that in emerging markets like Indonesia, audit committee independence and sound capital structure management play a more critical role in ensuring timely financial reporting than symbolic governance attributes such as board composition or gender diversity.