This thesis provides a qualitative investigation of the leader identity construction process, within the context of organizations. It takes a social constructionist approach to investigate this process and utilizes leadership identity construction theory (LICT), as proposed by DeRue and Ashford (2010), as a theoretical framework to inform the interpretation of the data. The thesis is comprised of three analytical chapters. The first chapter employed video methods to capture the real time identity claiming and granting process of teams and utilized interaction analysis to analyse how the individuals in the teams negotiated their leader and follower identities. The second analytical chapter consisted of 50 semi-structured interviews that focused on factors found to either help or hinder the leader identity construction process. The third analytical chapter further draws from the interview data and provides insights into the perceptions of organizational control over the leader identity construction process. The value of this thesis is that it provides both a micro and meso level analysis of the leader identity construction process by drawing on the behavioural components of the process while also addressing organizational level issues. Additionally, by engaging with data across the adult life span from university age students all the way to individuals at the cusp of retirement, this thesis provides a timely temporal look at leader identity construction. This thesis makes several contributions. It does so by providing key insights into how one's self-conception as a leader is shaped by interactions with others, and by demonstrating what types of relationship contribute to the leader identity construction process, and the manner in which they do so. This thesis also provides vital insights into how organizational structures control leader identity, while also bringing to light the challenges individuals face in constructing a leader identity.