Teacher professional development (PD) in reading is aimed at improving teachers' instructional practice and, in turn, positively impacting students' reading achievement. Findings from 25 studies included in this meta-analysis demonstrate that overall, reading PD produced significant, positive effects on teacher outcomes (g = 0.62). The overall effects of reading PD on teacher skills were large and significant (g = 0.64), while the effects of reading PD on teachers' beliefs were small and nonsignificant (g = 0.25). Findings also demonstrated significantly larger effects for active participation, providing teachers with opportunities to learn how to implement an evidence-based practice compared to passive participation. More research is needed to better understand other key features of high-quality reading PD, including coherence or alignment of PD content with school and district initiatives and needs to determine the necessary dosage of PD required to maximize teacher outcomes.