The purpose of this paper is to investigate the drivers of firms’ sociability on social media (SM), an unregulated area, in an emerging country, namely, Kingdom of Saudi Arabia (KSA). The sample of this study is 345 non-financial listed firms on Tadawul stock exchange during 2016-2019. Data are collected from several sources such as annual reports, the official website of the sample companies. Other data are collected manually such as the presence of the CEO and the sampled companies on SM. Our findings show that firm size and leverage level are important firms’ characteristics that drive firms’ sociability on social media. The finding shows that CEO sociability on social media is a key CEOs’ characteristic that drives firms’ sociability on social media. Further analysis reports that there is a complementary effect between CEO’s sociability on social media and firm size in increasing firms’ sociability on SM. The findings also show that there is a complementary effect between CEO’s sociability on social media and firm leverage in increasing firms’ sociability on SM. This study contributes to the disclosure literature by providing empirical evidence of the drivers of firms’ sociability on SM, an unregulated area in KSA. It also complements the considerable literature on voluntary disclosure which ignores the use of SM platforms as a “new” voluntary type of reporting. The present study complements recent literature on the adoption of SM by providing evidence that the sociability of top leaders is a driver of firms’ sociability on SM.