Providing teachers effective professional development (PD) is an ongoing challenge in the field of education. Emergence of technological innovations in the form of computer-based asynchronous and synchronous communication has provided new opportunities to improve and expand teacher PD opportunities beyond the physical walls of a school. The purpose of this meta-analysis is to examine the ability of online learning environments to facilitate the critical features of teacher PD identified in Desimone (2009) as content focus, active learning, coherence, duration, and collective participation. Analysis of the 20 empirical studies sought to reveal the purpose of the study, methodologies utilized, and major findings. Multiple studies indicated the ability of an online environment to engage teachers in active learning, collective participation, and content-focused learning activities. Additionally, the results of this meta-analysis revealed a lack of empirical studies that have examined the ability of online teacher PD to support the critical features of coherence and duration. Findings of this research have implications for a future research agenda and policy considerations related to online teacher PD initiatives.