This systematic review examines research on heritage language (HL) teacher education conducted between 2010 and 2020. A total of 22 studies were analyzed to identify trends, focal areas, and challenges in HL teacher development. The findings reveal a substantial growth in publications over the decade, predominantly from North America, highlighting a pressing need for more global representation. Key themes include the need for specialized pedagogical training, teacher identity transformation, and addressing language ideologies. Despite progress, gaps persist in professional development opportunities and inclusive teacher preparation. The review underscores the importance of sociolinguistic awareness, reflective practices, and differentiated instruction in HL pedagogy and offers actionable recommendations for teacher education programs and policymakers.