In this paper, we outline how science teachers might engage in the work of creating educational equity. While acknowledging the historical inherent inequities associated with issues of access, opportunities to engage in science learning for individuals of marginalized identities (e.g., BIPOC individuals and women), and achievement, we broaden this definition to include social justice as a framework by which we can develop opportunities for the fostering of students' affinity identities with science. To this end, we draw on theorizations of equity within educational research, specifically discussed as excellence, equality, fairness, a zero-sum game, and most recently, social justice. Additionally, we utilize McKinney de Royston and Nasir's (2017) "Racialized Learning Ecologies" framework. This framework provides a useful lens to notice the layers of (in)equity within education. We then extend this ecological model into science education and present three lenses (i.e., layers) through which equity operates within science teaching and learning. We conclude with a discussion of the practical implications of doing the work of equity, that is, recognizing, interpreting, and redressing inequity in science classrooms. Ultimately, we provide an actionable definition of equity that has the potential to facilitate transformative and socially just science teaching and learning.