Research indicates that possession of a robust teacher identity reduces attrition from the classroom and improves retention in the teaching profession, which is nuanced by intersectional angles of gender, race, profession, and one's own perceptions. Emerging research suggests that teacher engagement in advocacy activities is also a vital component of retention, particularly among teachers of Science, Technology, Engineering, and Mathematics (STEM) subjects. To better understand advocacy activities engaged in by U.S. in/formal STEM teachers, the present study surveyed 413 individuals querying how they perceive and engage in advocacy activities for STEM education. Data related to identity were parsed by intersectional facets of gender, race, sector of education (in/formal), and one's own perception as an advocate, which were compared using Mann-Whitney U analyses from Social Issues Advocacy Scales to determine beliefs of what constituted advocacy activities and what they engaged in as an advocate for STEM education. Among identity groupings, results suggest that respondents who identified as "always an active advocate" had the most (n = 13) significant differences regarding perceptions of and participation in advocacy activities regarding STEM education. The present research proposes that a teacher's perceptions of being an advocate is an important part of shaping their STEM teacher advocate identity.