In recent years increasing attention has been given to systematic comparison of theories of consciousness. Laudable practical projects have emerged in this regard, such as adversarial collaboration and the development of databases lending themselves to comparisons of empirical support for theories. In addition to the practical advances, theoretical advances have been made, such as a list of issues a theory of consciousness must address. We propose adding the issue of the ontogenetic emergence (O-emergence) of consciousness to the list of issues we use to evaluate theories of consciousness. O-emergence concerns how and when consciousness emerges ontogenetically in human beings. The underlying assumption is that there exists a point in the development of a human individual before which that individual is not and cannot be conscious. This assumption, in turn, depends on a widely shared assumption of cognitive neuroscience, which is that consciousness somehow depends on — or derives from — brain activity. In this paper, we lay out the O-emergence criterion and investigate whether it can be accounted for within the Global Neuronal Workspace theory, the Self-Organizing Meta-representational Account, and the Reorganization of Elementary Functions framework.