The purpose of this article is to enhance the conceptual coherence of the notion of a self-initiated expatriate (SIE). We propose a definition based on a set of conceptual criteria which differentiates SIEs from other types of international movers. This article defines who an SIE is according to four criteria which must all be fulfilled at the same time: (a) self-initiated international relocation, (b) regular employment (intentions), (c) intentions of a temporary stay, and (d) skilled/professional qualifications. The article discusses each of these criteria in turn and their implications on what it means to be an SIE. A research agenda related to the four criteria proposes various avenues which scholars could take to expand this area of research. The literature on SIEs is rapidly emerging, but the lack of conceptual clarity in defining this type of expatriate is as acute as incomprehensible, given the importance of this group of international movers.