As one of the first empirical analyses focusing on corporate executive officers’ (CEOs) communication style on social media and its impacts, the study aims to advance the theoretical understanding of CEO sociability and the mechanism underneath its effects on the broader public relations outcome of organization–public relationship and public advocacy. Through a quantitative survey with 332 social media users who have followed corporate CEOs on social media, this study illuminated how CEOs’ responsive and assertive communications induce the CEOs’ followers to perceive the corporate leaders as amicable role models and caring friends, which in turn improve their trust of, satisfaction with, and advocacy for the company. Hence, the findings highlight the pivotal role of CEOs as chief engagement officer in developing meaningful interpersonal interactions and relationships with today’s digital savvy publics.