Purpose: This paper aims to examine the impact on diverse students' social equity outcome measures that result from incorporating social justice education and inclusive practices into an introductory course on sustainability offered online asynchronously, online synchronously and in-person. Design/methodology/approach: From fall 2020 to fall 2021, 706 students took "Introduction to Sustainability" at Michigan State University. A revised curriculum increased inclusive practices and social justice content centered on race and other social identities; institutional, individual and implicit bias; interrupting bias; socialization; and spheres of influence. Students' self-reported change was examined using a retrospective pre/post survey. Findings: Students reported significant growth in social equity understanding and practice across teaching modes with in-person instruction associated with the largest reported growth. Students reported growth regardless of their racial/ethnic identity or gender, with instructor effects varying in expected ways. The gap in social equity understanding between students with low precourse ratings (on outcome measures) and those with high precourse ratings was significantly smaller after the course. Research limitations/implications: This study is not without limitations. First, the authors were limited in the student-specific information that they could collect. Second, the authors did not have access to an alternative course that could serve as a control. Third, the authors did not have the resources to also conduct an in-depth, thorough qualitative study. Furthermore, the authors did not conduct their investigation during "normal" campus life because it took place during the height of the COVID-19 pandemic. The pandemic was a factor that could not be accounted for and might have impacted the outcomes. Originality/value: This study is novel in identifying and incorporating specific social justice education material, tools and practices for improved teaching of social equity components of sustainability.