This systematic literature review explored the importance of professional development (PD) for educators working with gifted students. Findings highlighted the need for PD to improve teacher knowledge, skills, efficacy, and student outcomes, especially considering the heterogeneously grouped classrooms, unique student needs, and lack of pre-service gifted education training for most teachers. The review identified key themes including PD evaluation, teacher perceptions, and pedagogical practices. The findings suggested that effective PD programs should (a) enhance knowledge and classroom practice, (b) be evidence-based, (c) consider both teacher and student outcomes, (d) be of sustained duration, and (e) include collaborative activities with ongoing mentoring support. Equally important was school leadership support such as the development of policies and allocation of resources (e.g., time). Recommendations include PD focused on the use of project/problem-based learning, quality differentiation, and consideration of the context in which the PD is delivered. Overall, this literature review underscores the importance of ongoing PD for educators working with gifted students and the need for additional empirical research focused on changing teacher practices and impact on student outcomes.