ABSTRACT This paper examines the development and validation of the Survey of Elementary Teachers’ Sense of Agency (SETSA), which investigates elementary science teachers’ sense of agency for teaching science. How elementary teachers express agency is critical to the learning outcomes of youth, particularly because elementary classrooms often serve as foundational sites for science experiences. Yet, elementary science teachers’ sense of agency for teaching science is understudied. Therefore, we developed the SETSA through a rigorous, systematic process. Development and validation of the SETSA occurred in multiple phases. Experts examined initial survey items, which were revised and consolidated into the 49-item SETSA. This was piloted with elementary teachers and the results led to a refined version. This later survey was administered to current teachers in elementary classrooms throughout the United States, with 1680 teachers responding. Analyses supported a robust, 10-factor model, which is consistent with frameworks and constructs in the current literature. Factors included in an elementary teacher's sense of agency for teaching science were: structures, science teacher identity, relationships, emotions, experience, professional vision. Factors included in an elementary teacher's expressions of that agency were: structure negotiation, science teacher identity negotiation, change in teacher practice and teaching with a justice orientation.