Social media has changed the social landscape in which public relations (PR) is conducted. This article explores the relationship between social media and PR practice, drawing on the Nigerian experience and with a comparative perspective on other emerging economies. This paper participates in a discussion about the nature of social media and public communication, conceptualising the phenomenon using the lens of the 'Situational Theory of Publics' and 'Environmental Systems Theory' to illustrate that social media is democratising public communication, creating multiple stakeholder publics, and hastening the pace and complexity of reputation management. Nigeria, which has more than 33 million social media users, deep-seated digital inequalities, and an active but volatile online civic culture, offers a unique set of opportunities and challenges for PR practitioners. The article identifies key dynamics including citizen journalism, online activism, ethnic and religious mobilisation online, and influencer ecosystems, analysing their implications for how organisations manage their relationships with various publics. Based on the paper's findings, it is concluded that PR practice in Nigeria must be context-sensitive, culturally intelligent, and digitally responsive to effectively and ethically navigate the changing social landscape.