In-service teachers of science work with unique content and pedagogical experiences within a changing educational landscape. Understanding teacher agency in these circumstances will help researchers understand the actions that these teachers take. The purpose of this meta-analysis was to review how the agency of K-12 in-service teachers of science has been examined empirically in the science education research literature during the period of 2007-2020. Informed by grounded theory, we qualitatively analyzed 48 peer-reviewed articles, which we located using specific search criteria. We identified that science teacher agency is currently conceptualized largely paper-to-paper and without fully attending to the professional and lived experiences, and thus humanity, of science teachers; thereby, creating exciting opportunities for science education researchers to expand on both the breadth and depth around the theorization and operationalization of in-service science teacher agency. Recommendations are addressed.