Research on in-service Science, Technology, Engineering, and Math (STEM) Teacher Professional Development (TPD) has received attention in the last decade, but has not produced conclusive findings. This study aimed to examine the trends of STEM TPD programmes by applying several proposed frameworks. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses were employed to analyse 44 journal articles on in-service STEM TPD programmes. The results of this study revealed that constructivist theory was the most widely adopted learning theories. Moreover, workshop, training, and online TPD were the most frequently used learning models. The research conclusion indicates that future STEM TPD requires more involvement of school principals in encouraging STEM teachers to develop their professionalism through the necessary in-service TPD programs.