The study examines whether audit committee (AC) characteristics influence firm performance, and whether this relationship is moderated by board of director’s (BOD) ownership. The sample is listed manufacturing firms in Jordan. AC characteristics, as an indicator of corporate governance mechanism, include its size, meeting frequency, independence, and experience. Firm performance is proxied by return on assets (ROA). Thirty firms are included in the sample. Data are collected from 2015 to 2021 for a total of 210 observations. The first model indicates that AC meetings and independence positively and significantly influence firm performance. On the other hand, AC size is not a significant predictor of firm performance. The second model shows that the interaction effects (AC size, AC independence, and AC experience) are significant and positive on firm performance. The results provide insights on how to improve AC effectiveness so as to improve the performance of listed manufacturing firms in Jordan. They also suggest the significance of BOD ownership in enhancing internal corporate governance mechanisms, particularly the AC. Jordanian policy makers must therefore ensure the effectiveness of these mechanisms, especially AC, through relevant regulations and recommendations.