This thesis investigates the intellectual capital (IC, hereafter) disclosure practices of large Australian companies and their determinants. According to signalling theory, companies provide a signal of important information through their disclosures to promote their competitive advantage. This important information includes IC (Oliveira, 2006). Prior research (Guthrie & Petty, 2000) documents how the Australian economy has shifted to a knowledge-based one. Recent innovation initiatives launched by the Australian government in 2015 (Australian Financial Review, 2015b) also show how important IC is for Australian and companies and the Australian economy. Prior research (for example Guthrie, Petty, and Ricceri (2006), Wagiciengo and Belal (2012), Bozzolan, Favotto, and Ricceri (2003), among others) has documented IC disclosure practices worldwide. However, the majority of this research was focused on annual reports and company websites. The emergence of social media brings advantages for company disclosures such as a two-way communication and the flexibility to access information on a timely basis. In Australia, the majority of social media users are Facebook users (Sensis, 2016). Considering the popularity of Facebook in Australia, this thesis analyses whether and how Facebook is being used by Australian companies to disclose IC. Its first research question examines whether Australian companies use annual reports, company websites, and Facebook to disclose their IC information. According to stakeholder theory, a company needs to meet stakeholder demands to achieve its strategic objectives (Robert, 1992). In this regard, prior research has documented the importance of IC disclosures to assist investors’ decision making (Andriessen, 2004). Thus, a company recognises the importance of IC and needs to provide the disclosure. Media agenda setting theory suggests that a company may use different media in order to effectively reach their wide stakeholders. Considering this, the second research question of this thesis investigates whether Australian companies put any different emphasis about their IC disclosures in those three different media. The last research question addresses the determinants of IC disclosures. As the board of directors is influential in dealing with external stakeholders (Pfeffer, 1972), and constitute the highest decision control system and monitoring role in a company (Fama & Jensen, 1983), this thesis focuses on the influence of the board in companies’ IC disclosure practices. Specifically, this thesis investigates the board members’ education, expertise, and gender. To drill down into the extent of IC disclosures in these three different media, this thesis explores the IC disclosure scores by employing exploratory factor analysis. The research samples were drawn from companies listed in the ASX 500. Furthermore, this thesis applies multivariate regression analysis to explore the determinants of IC disclosures. The results of this thesis contribute to the IC disclosure literature by providing evidence on the usage of Facebook in IC disclosures. As this platform’s usage is evident, this may encourage more companies to use it to communicate with stakeholders. Moreover, this thesis finds that while Australian companies use all three different media to disclose their IC information, they put a different emphasis on these distinct media. Furthermore, this thesis suggests that stakeholders need to pay attention to several forms of media for IC related information. This thesis contributes to the board diversity literature by investigating the relationship between the board of directors and the quantity of IC disclosures. Findings include that board members’ characteristics determine a company’s IC disclosures in annual report and company websites. However, this research argues that Facebook is a relatively new avenue for Australian companies to provide IC disclosures and it is being used by them to reach out to the millennial generations. Furthermore, this study also suggests that a company may pay attention to some board members’ characteristics that may be associated with a higher level of disclosures.